A mixture contains 25 g of cyclohexane (C6H12) and 44 g of 2-methylpentane (C6H14). The mixture of liquids is at 35 oC . At this temperature, the vapor pressure of pure cyclohexane is 150 torr, and that of pure 2-methylpentane is 313 torr. Assume this is an ideal solution. What is the mole fraction of cyclohexane in the liquid phase?

Answers

Answer 1

Answer:

The mol fraction of cyclohexane in the liquid phase is 0.368

Explanation:

Step 1: Data given

Mass of cyclohexane = 25.0 grams

Mass of 2-methylpentane = 44.0 grams

Temperature = 35.0 °C

The pressure of cyclohexane = 150 torr

The pressure of 2-methylpentane = 313 torr

The pressure we only need for the mole fraction in gas phase.

Step 2: Calculate moles of cyclohexane

Moles cyclohexane = mass cyclohexane / molar mass

Moles cyclohexane = 25.0 g / 84 g/mol = 0.298 mol of cyclohexane

Step 3: Calculate moles of 2-methylpentane

Moles = 44.0 grams / 86 g/mol = 0.512 mol of 2-methylpentane

Step 4: Calculate mole fraction of cyclohexane in the liquid phase

Mole fraction of C6H12:

0.298 / (0.298 + 0.512) = 0.368

The mol fraction of cyclohexane in the liquid phase is 0.368

Answer 2
Final answer:

The mole fraction of cyclohexane in the liquid phase is 36.8%.

Explanation:

To find the mole fraction of cyclohexane in the liquid phase, we need to calculate the total moles of cyclohexane and 2-methylpentane in the mixture. First, we calculate the moles of each component using their molar masses:

moles of cyclohexane = 25 g / 84.18 g/mol = 0.297 mol

moles of 2-methylpentane = 44 g / 86.18 g/mol = 0.509 mol

Next, we calculate the mole fraction of cyclohexane:

mole fraction of cyclohexane = moles of cyclohexane / (moles of cyclohexane + moles of 2-methylpentane)

mole fraction of cyclohexane = 0.297 mol / (0.297 mol + 0.509 mol) = 0.368 or 36.8%


Related Questions

Which of the following is a definition of glass transition temperature?

The temperature at which a glass transforms from a solid to liquid.

The temperature at which a glass transforms from a liquid to solid.

The temperature at which there is a slight decrease in the slope of the temperature versus specific volume curve.

Answers

The glass transition temperature ([tex]T_g[/tex]) is the temperature at which there is a slight decrease in the slope of the temperature versus specific volume curve.

Glass transition temperature ([tex]T_g[/tex]) is defined as the temperature at which there is a slight decrease in the slope of the temperature versus specific volume curve.

Unlike the melting point, which involves a phase change from solid to liquid, the glass transition temperature is a continuous transition where a supercooled liquid transitions into a glassy, rigid state.

This process does not involve a complete change of state but rather the material's internal structure becoming more rigid. At temperatures above [tex]T_g[/tex], the material behaves more like a quasi-equilibrium liquid, whereas below [tex]T_g[/tex], reorganization among structural units ceases, and the material becomes more glass-like in its properties.

What are the coefficients of the reactants and products in the balanced equation above? Remember to include H2O(l) and OH−(aq) in the blanks where appropriate. Your answer should have six terms. Enter the equation coefficients in order separated by commas (e.g., 2,2,1,4,4,3). Include coefficients of 1, as required, for grading purposes.

Answers

The order of coefficients of the reactants and products in the balanced reaction is 1,3,6,1,3,3.

[tex]BrO_3^- (aq) + Sn^{2+} + H^+ \longrightarrow Br^- + Sn^{4+} + H_2O.[/tex]

What is the balanced chemical equation?

The chemical equation in which the number of atoms of reactants and products is equal on either side of the equation is known as a balanced chemical equation.

According to the law of conservation of mass, the total mass on the reactant side should be equal to the total mass on the product side in a chemical equation

The given unbalanced chemical equation is as follows:

[tex]BrO_3^- (aq) + Sn^{2+} + H^+ \longrightarrow Br^- + Sn^{4+} + H_2O.[/tex]

To balance this equation, the coefficients are placed as shown below:

[tex]BrO_3^- (aq) + 3Sn^{2+} +6 H^+ \longrightarrow Br^- + 3Sn^{4+} + 3H_2O.[/tex]

Therefore, the order of the coefficient of reactants and products in the balanced equation is (1,3,6,1,3,3).

Learn more about the balanced chemical equation, here:

brainly.com/question/15052184

#SPJ5

Your question was incomplete, most probably the complete question was,

Consider the reaction given as

BrO₃⁻ (aq) + Sn²⁺ + __ → Br⁻ + Sn⁴⁺ + __

What are the coefficients of the reactants and products in the balanced equation above? Remember to include H2O(l) and H+(aq) in the appropriate blanks. Your answer should have six terms. Enter the equation coefficients in order separated by commas (e.g., 2,2,1,4,4,3). Include coefficients of 1, as required, for grading purposes.

A lead–tin alloy of composition 30 wt% Sn–70 wt% Pb is slowly heated from a temperature of 150°C (300°F).(a) At what temperature does the first liquid phase form?(b) What is the composition of this liquid phase?(c) At what temperature does complete melting of the alloy occur?(d) What is the composition of the last solid remaining prior to complete melting?

Answers

Answer:

a) 231.9 °C

b) 100% Sn

c) 327.5 °C

d) 100% Pb

Explanation:

This is a mixture of two solids with different fusion point:

[tex]Tf_{Pb}=327.5 C[/tex]

[tex]Tf_{Sn}=231.9 C[/tex]

Given that Sn has a lower fusion temperature it will start to melt first at that temperature.

So the first liquid phase forms at 231.9 °C and because Pb starts melting at a higher temperature, that phase's composition will be 100% Sn.

The mixture will be completely melted when you are a the higher melting temperature of all components (in this case Pb), so it will all in liquid phase at 327.5 °C.

At that temperature all Sn was already in liquid state and, therefore, the last solid's composition will be 100% Pb.

Rank the following materials from highest BP to lowest BP: a. N2, NaF, NH3, Ni, HIb. Ag, H20, Ar, HBr, KC c. LiF, Fe, F2. HF, HCI

Answers

Explanation:

Metallic solids are defined as the solids in which atoms of metals are held together by metallic bonds. These bonds are much stronger than an ionic bond.

In metallic solids, the electrons are delocalized in nature. On the other hand, ionic solids have strong bonds due to the presence of opposite charges on its combining atoms.

Molecular solids are defined as the solids in which atoms are combined together through Vander waal forces. Hence, molecular solids have low boiling point.

(a) It is known that [tex]N_{2}[/tex] is a molecular solid, NaF is an ionic solid, in [tex]NH_{3}[/tex] there exists hydrogen bonding between the molecules, and Ni is a metallic solid. Hence, the given materials are placed according to highest B.P. to lowest B.P. as follows.

            Ni > NaF > [tex]NH_{3}[/tex] > HI > [tex]N_{2}[/tex]

(b)   Ag is a metallic solid, and KCl is an ionic solid. Oxygen atom is more electronegative than bromine atom. So, the boiling point of [tex]H_{2}O[/tex] is more than the boiling point of HBr. Whereas Ar is a noble gas and it has low boiling point.

Hence, the given materials are placed according to highest B.P. to lowest B.P. as follows.

             Ag > KCl > [tex]H_{2}O[/tex] > HBr > Ar

(c)    Fe is also a metallic solid and electronegativity of fluorine is more than the electronegativity of chlorine. Hence, HF has high boiling point than HCl. And, [tex]F_{2}[/tex] being a covalent compound has weak intermolecular forces. So, the boiling point of [tex]F_{2}[/tex] will be the least.

Therefore, the given materials are placed from highest B.P. to lowest B.P. as follows.

           Fe > LiF > HF > HCl > [tex]F_{2}[/tex]  

Final answer:

To rank the boiling points from highest to lowest, identify the type of bonding and intermolecular forces present in each substance: ionic, metallic, hydrogen bonding, dipole-dipole interactions, or London dispersion forces. Ionic and metallic bonds generally lead to higher boiling points than molecular compounds.

Explanation:

The student has asked a Chemistry question regarding the ranking of the boiling points (BP) of different substances. Boiling points can be compared using intermolecular forces: ionic bonds, hydrogen bonds, dipole-dipole interactions, and London dispersion forces. Ionic compounds like NaF typically have higher boiling points than covalent compounds due to the strong electrostatic force between ions.

Metallic bonds found in metals like Ni also exhibit high boiling points. Among covalent compounds, the presence of hydrogen bonding, as found in NH3, would lead to a higher boiling point than compounds that rely solely on dipole-dipole interactions (such as HF) or London dispersion forces (like N₂ and HBr).

Given this, we would rank the boiling points from highest to lowest as:

a. NaF > Ni > NH₃ > HI > N₂,

b. Ag > HBr > KC > H₂O > Ar

c. F₂ > Fe > LiF > HCI > HF

assuming the compounds are in pure form and standard atmospheric pressure is taken into account.

You can measure how much of something you have by counting individual objects. For example, you can count the number of cookies in a bag or the number of pages in your notebook. There is a name for a number of atoms, ions, or molecules. One mole of a substance is equal to 6.02 x 10^23 atoms, ions, or molecules of that substance. You can determine the number of moles in a substance by obtaining the mass of the substance.

Objectives
• To measure the masses of common compounds and objects
• To calculate the moles and atoms from the experimental masses

a. Salt(NaCl)
b. Sugar(C6H22O11)
c. Chalk(CaCO3)
d. Sand(SiO2)
e. Water(H2O)
f. Balance
g. Spoon

Answers

Answer:

Explanation: first use a balance to get the masses of these items. Once the masses of these items are measured, we can then calculate the moles.

The mole is = mass/molarmass

At shipper’s dock you are given a shipping paper for 100 cartons of battery acid. You already have 100 pounds of dry Silver Cyanide on board. What precautions do you have to take?

Answers

Answer:

At the shipper's dock when it already has the 100 cartons of battery acid, 100 pounds of dry silver cyanide should not be loaded together.

Explanation:

The dry silver cyanide and battery acid are list of products that has been restricted from taking together while travelling because of safety reasons. This has been already present in the "Do not load" division 6.1 i.e. materials such as silver cyanide cannot be loaded with acid or any other corrosive material which could react to make hydrocyanic acid. As hydocyanic acid is an oxidant and would be an agent that help in igniting combustibles like wood, paper oil and clothing.

Which of the following units for distance is an Sl unit?
1)Centimeter
2)Foot
3)Inch
4) yard

Answers

Answer:

Option a, centimeter

Explanation:

Foot, Inch and Yard are units used in America, UK, and other english-speaking countries.

These countries are currently reviewing the possibility of adapting the measures to the SI. The centimeter is a unit derived from the meter, base unit for measuring length in the SI, and corresponds to the cgs system, where in addition to the centimeter, is constituted by gram and second units

Percent Ionization
Percent ionization for a weak acid (HA) is determined by the following formula:

Percent ionization=[HA] ionized[HA] initial×100%

For strong acids, ionization is nearly complete (100%) at most concentrations. However, for weak acids, the percent ionization changes significantly with concentration. The more diluted the acid is, the greater percent ionization.
A certain weak acid, HA, has a Ka value of 7.6×10−7.
Part A
Calculate the percent ionization of HA in a 0.10 M solution.
Express your answer as a percent using two significant figures.

%

SubmitHintsMy AnswersGive UpReview Part
Part B
Calculate the percent ionization of HA in a 0.010 M solution.
Express your answer as a percent using two significant figures.

%

Answers

Answer:

(a) 0.26 % (b) 0.80 %

Explanation:

(a)

Given that:

[tex]K_{a}=7.6\times 10^{-7}[/tex]

Concentration = 0.10 M

Considering the ICE table for the dissociation of acid as:-

[tex]\begin{matrix}&HA&\rightleftharpoons &A^-&&H^+\\ At\ time, t = 0 &0.10&&0&&0\\At\ time, t=t_{eq}&-x&&+x&&+x\\ ----------------&-----&-&-----&-&-----\\Concentration\ at\ equilibrium:-&0.10-x&&x&&x\end{matrix}[/tex]

The expression for dissociation constant of acid is:

[tex]K_{a}=\frac {\left [ H^{+} \right ]\left [ {A}^- \right ]}{[HA]}[/tex]

[tex]7.2\times 10^{-7}=\frac{x^2}{0.10-x}[/tex]

[tex]7.2\left(0.10-x\right)=10000000x^2[/tex]

Solving for x, we get:

x = 0.00026  M

Percentage ionization = [tex]\frac{0.00026}{0.10}\times 100=0.26 \%[/tex]

(b)

Concentration = 0.010 M

Considering the ICE table for the dissociation of acid as:-

[tex]\begin{matrix}&HA&\rightleftharpoons &A^-&&H^+\\ At\ time, t = 0 &0.010&&0&&0\\At\ time, t=t_{eq}&-x&&+x&&+x\\ ----------------&-----&-&-----&-&-----\\Concentration\ at\ equilibrium:-&0.010-x&&x&&x\end{matrix}[/tex]

The expression for dissociation constant of acid is:

[tex]K_{a}=\frac {\left [ H^{+} \right ]\left [ {A}^- \right ]}{[HA]}[/tex]

[tex]7.2\times 10^{-7}=\frac{x^2}{0.010-x}[/tex]

[tex]7.2\left(0.010-x\right)=10000000x^2[/tex]

Solving for x, we get:

x = 0.00008  M

Percentage ionization = [tex]\frac{0.00008}{0.010}\times 100=0.80 \%[/tex]

How many electrons are transferred in the following reaction?

(The reaction is unbalanced.)

Mg(s) + Al3+(aq) → Al(s) + Mg2+(aq)

Answers

Answer:

6

Explanation:

Oxidation reaction is defined as the chemical reaction in which an atom looses its electrons. The oxidation number of the atom gets increased during this reaction.

[tex]X\rightarrow X^{n+}+ne^-[/tex]

Reduction reaction is defined as the chemical reaction in which an atom gains electrons. The oxidation number of the atom gets reduced during this reaction.

[tex]X^{n+}+ne^-\rightarrow X[/tex]

For the given chemical reaction:

[tex]Mg(s)+Al^{3+}(aq.)\rightarrow Al(s)+Mg^{2+}(s)[/tex]

The half cell reactions for the above reaction follows:

Oxidation half reaction:  [tex]Mg\rightarrow Mg^{2+}+2e^-[/tex]

Reduction half reaction:  [tex]Al^{3+}+3e^-\rightarrow Al[/tex]

Magnesium is loosing 2 electrons to form the magnesium cation. Thus, it is getting oxidized. Aluminum anion is gaining 3 electrons to form Aluminum. Thus, it is getting reduced.

Thus, balancing the half-reactions as:-

Oxidation half reaction:  [tex]3Mg\rightarrow 3Mg^{2+}+6e^-[/tex]

Reduction half reaction:  [tex]2Al^{3+}+6e^-\rightarrow 2Al[/tex]

Thus, total number of electrons transferred = 6

Answer:

3Mg +2Al^3 ⇆ 3 Mg^2+ + 2Al

In this reaction 6 electrons are transferred

Explanation:

Step 1: The half reactions

Mg  -2e- ⇆ Mg^2+

Al^3+ +3e- ⇆ Al

Step 2: Balance both equations

3*(Mg  -2e- ⇆ Mg^2+)

2(Al^3+ +3e- ⇆ Al)

3Mg  -6e- ⇆ 3Mg^2+

2Al^3+ +6e- ⇆ 2Al

Step 3: The netto reaction

3Mg +2Al^3 ⇆ 3 Mg^2+ + 2Al

In this reaction 6 electrons are transferred

which of the following pieces of laboratory glassware should be used to most accurately measure out a 25.00 ml sample of a solution?
Ii. Out of a 25 mL graduated cylinder, 150 mL beaker, and a 50 mL Erlenmeyer flask which has the least uncertainty (most accurate volume)? Explain iii. If you had to accurately measure 20 mL of a liquid which of the three pieces of glassware would you use, 25 mL graduated cylinder, 150 mL beaker or a 50 mL? Explain

Answers

Final answer:

To most accurately measure out a 25.00 mL sample of a solution, a 25 mL graduated cylinder should be used. The same graduated cylinder can also be used to accurately measure 20 mL of a liquid.

Explanation:

In order to most accurately measure out a 25.00 mL sample of a solution, a 25 mL graduated cylinder should be used. A graduated cylinder is designed with calibrated markings that allow for precise measurement of volume. It typically has a smaller uncertainty or error compared to a beaker or an Erlenmeyer flask.

If you had to accurately measure 20 mL of a liquid, you would still use the 25 mL graduated cylinder. Even though the cylinder has a larger capacity, it can still accurately measure smaller volumes. It is important to note that using a piece of glassware with a larger capacity than the required volume ensures that there is no spillage during the measurement process.

Learn more about Measurement of liquid volume here:

https://brainly.com/question/28246821

#SPJ12

Final answer:

The most accurate piece of laboratory glassware to measure out a 25.00 mL sample of a solution would be a 25 mL graduated cylinder. If you had to accurately measure 20 mL of a liquid, the best choice among the three options would still be the 25 mL graduated cylinder.

Explanation:

The most accurate piece of laboratory glassware to measure out a 25.00 mL sample of a solution would be a 25 mL graduated cylinder. A graduated cylinder is designed to measure liquid volume with good accuracy. The markings on the cylinder allow for precise measurements, usually to the nearest 0.1 mL. By using the markings and reading the bottom of the meniscus, you can determine the volume of the solution.

If you had to accurately measure 20 mL of a liquid, the best choice among the three options would still be the 25 mL graduated cylinder. Although the graduated cylinder has a larger capacity than the required volume, it still provides accurate measurements within its range. It allows for better precision compared to a beaker or an Erlenmeyer flask.

Learn more about accurate measurement of liquid volume here:

https://brainly.com/question/11093299

#SPJ3

Linoleic acid is a polyunsaturated fatty acid found, in ester form, in many fats and oils. Its doubly allylic hydrogens are particularly susceptible to abstraction by radicals, a process that can lead to the oxidative degradation of the fat or oil. The radical formed by abstraction of one of the doubly allylic hydrogens is an allylic radical that has three resonance structures. Complete one of these resonance structures by dragging bonds and electrons to their appropriate positions.

Answers

Final answer:

Linoleic acid is a polyunsaturated fatty acid that forms an allylic radical with three resonance structures when its doubly allylic hydrogens are abstracted by radicals. These types of fats are liquid at room temperature and are nutritionally significant due to the body's inability to produce them. They carry numerous health benefits, including heart health and anti-cancer properties.

Explanation:

Linoleic acid is a polyunsaturated fatty acid found in various fats and oils. The hydrogen atoms in its doubly allylic positions are readily abstracted by radicals, leading to the oxidative degradation of the fat or oil. The resulting radical, called an allylic radical, has three resonance structures. Completing one resonance structure involves correctly positioning bonds and electrons.

Linoleic acid, like other polyunsaturated fats, can have more than one double bond in its structure. These fats are usually liquid at room temperature, like canola oil. When a fatty acid has a double bond in its structure, it is classified as unsaturated. Polyunsaturated fatty acids such as omega-3 fatty acids are nutritionally important because the human body cannot manufacture them. They must be obtained from the diet.

Fatty acids such as omega-3 fatty acids have a number of health benefits. They reduce the risk of heart attacks, reduce blood triglyceride levels, decrease blood pressure, and prevent thrombosis by inhibiting blood clotting. They also have anti-inflammatory properties and may help lower the risk of certain cancers.

Learn more about polyunsaturated fats here:

https://brainly.com/question/13141983

#SPJ3

An analytical chemist weighs out of an unknown diprotic acid into a volumetric flask and dilutes to the mark with distilled water. He then titrates this solution with solution. When the titration reaches the equivalence point, the chemist finds he has added of solution. Calculate the molar mass of the unknown acid. Be sure your answer has the correct number of significant digits.

Answers

Final answer:

The molar mass of an unknown diprotic acid is determined through a titration procedure. Using the volume and molarity of NaOH, we calculate the moles of NaOH, then divide by 2 to get the moles of diprotic acid. Dividing the mass of the acid by the moles gives us the molar mass.

Explanation:

In this problem, the student is asked to calculate the molar mass of an unknown diprotic acid. The task requires the understanding of acids, stoichiometry, and titration concepts in analytical chemistry.

A diprotic acid is an acid that can donate two protons, or hydrogen ions, per molecule in solution. As the question doesn't provide the exact values, I'll explain conceptually. The molar mass of the unknown acid is calculated by using the volume of NaOH needed to reach the equivalence point and the concentration of NaOH. We'd start by calculating the moles of NaOH used (moles = volume x molarity), then because it's a diprotic acid, for every mole of acid, two moles of NaOH are needed, so we'd divide the moles of NaOH by 2 to get moles of unknown acid (moles acid = moles NaOH / 2). Lastly to find the molar mass, divide the mass of the acid used by the moles of acid calculated. So, the molar mass = mass of acid / moles of acid.

Learn more about diprotic acid here:

https://brainly.com/question/31732916

#SPJ12

Final answer:

The titration analysis provides a method to calculate the molar mass of an unknown acid using the volume of a known solution required to reach the equivalence point of the reaction. The process involves incrementally adding the known solution to the unknown, and using the reaction stoichiometry to find the unknown concentration. The molar mass is then calculated from this concentration, the initial volume of solution, and the molecular formula of the reaction products.

Explanation:

Based on the information provided, we need further details to accurately calculate the molar mass of the unknown diprotic acid. However, we can understand the general process involved in calculating such values using titration data.

The process is generally as follows:

Titration analysis is conducted by incrementally adding a solution of known concentration (the titrant) to the unknown solution (analyte).The titrant and analyte undergo a chemical reaction of known stoichiometry. The volume of titrant required to reach the 'equivalence point' of the reaction - where both the titrant and analyte have been completely reacted - allows us to calculate the concentration of the unknown analyte solution. The molar mass of the unknown acid can then be calculated using the resulting concentration, the initial volume of solution, and the defined molecular formula and mass of the reaction products.

Learn more about Titration here:

https://brainly.com/question/31271061

#SPJ11

Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide according to the chemical equation shown below.
When 0.0 25 mol of Na is added to 100.00 g of water, the temperature of the resulting solution rises from 25.00°C to 35.75°C.

If the specific heat of the solution is 4.18 J/(g · °C), calculate ΔH for the reaction, as written.

2 Na(s) + 2 H2O(l) → 2 NaOH(aq) + H2(g) ΔH= ?

Answers

Answer: The enthalpy change of the reaction is -361.6 kJ

Explanation:

To calculate the number of moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

Moles of sodium = 0.025 moles

Molar mass of sodium = 23 g/mol

Putting values in above equation, we get:

[tex]0.025mol=\frac{\text{Mass of sodium}}{23g/mol}\\\\\text{Mass of sodium}=(0.025mol\times 23g/mol)=0.575g[/tex]

We are given:

Mass of water = 100.00 g

Mass of sodium = 0.575 g

Mass of solution = 100.00 + 0.575 = 100.575 g

To calculate the amount of heat absorbed, we use the equation:

[tex]q=m\times C\times \Delta T[/tex]

where,

q = amount of heat absorbed = ?

m = mass of solution = 100.575 g

C = specific heat capacity of solution = 4.18 J/g°C

[tex]\Delta T[/tex] = change in temperature = [tex](T_2-T_1)=(35.75-25.00)=10.75^oC[/tex]

Putting all the values in above equation, we get:

[tex]q=100.575g\times 4.18J/g^oC\times 10.75^oC=4519.34J=4.52kJ[/tex]

When heat is absorbed by the solution, this means that heat is getting released by the reaction.

Sign convention of heat:

When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.

For the given chemical reaction:

[tex]2Na(s)+2H_2O(l)\rightarrow NaOH(aq.)+H_2(g)[/tex]

When 0.025 moles of sodium is reacted, the heat released by the reaction is 4.52 kJ

So, when 2 moles of sodium will react, the heat released by the reaction will be = [tex]\frac{4.52}{0.025}\times 2=361.6kJ[/tex]

Hence, the enthalpy change of the reaction is -361.6 kJ

Final answer:

To calculate ΔH for the reaction, we can use the equation ΔH = q / n, where q is the heat transferred and n is the number of moles involved in the reaction. Given the mass of the solution, specific heat, and temperature change, we can calculate the heat transferred and use it to find ΔH.

Explanation:

The given chemical reaction is:

2 Na(s) + 2 H₂O(l) → 2 NaOH(aq) + H₂(g)

To calculate ΔH for the reaction, we can use the equation:

ΔH = q / n

Where:

ΔH is the enthalpy changeq is the heat transferredn is the number of moles involved in the reaction

Given that 0.025 mol of Na is added to 100.00 g of water and the temperature rise is 10.75°C, we can calculate the heat transferred:

q = m × c × ΔT

Where:

m is the mass of the solution in grams (100.00 g in this case)c is the specific heat of the solution (4.18 J/(g · °C) in this case)ΔT is the temperature change (35.75°C - 25.00°C = 10.75°C in this case)

After calculating q, we can use it to find ΔH:

ΔH = q / n

Substituting the values, we get:

ΔH = q / n = (m × c × ΔT) / n

So, ΔH for the reaction is the calculated value.

Learn more about Enthalpy Change here:

https://brainly.com/question/35890036

#SPJ6

Express the following numbers in scientific notation:

a. 60200 L
b. 4520 J
c. 0.00600 mg
d. 0.01023 km
e. 80.70 mL

Answers

Answer :

(a) The number in scientific notation is, [tex]6.0200\times 10^4L[/tex]

(b) The number in scientific notation is, [tex]4.520\times 10^3J[/tex]

(c) The number in scientific notation is, [tex]6.00\times 10^{-3}mg[/tex]

(d) The number in scientific notation is, [tex]1.023\times 10^{-2}km[/tex]

(e) The number in scientific notation is, [tex]8.070\times 10^1mL[/tex]

Explanation :

Scientific notation : It is the representation of expressing the numbers that are too big or too small and are represented in the decimal form with one digit before the decimal point times 10 raise to the power.

For example :

5000 is written as [tex]5.0\times 10^3[/tex]

889.9 is written as [tex]8.899\times 10^{-2}[/tex]

In this examples, 5000 and 889.9 are written in the standard notation and [tex]5.0\times 10^3[/tex]  and [tex]8.899\times 10^{-2}[/tex]  are written in the scientific notation.

[tex]8.89\times 10^{-2}[/tex]  this is written in the scientific notation and the standard notation of this number will be, 0.00889.

If the decimal is shifting to right side, the power of 10 is negative and if the decimal is shifting to left side, the power of 10 is positive.

(a) As we are given the 60200 L in standard notation.

Now converting this into scientific notation, we get:

[tex]\Rightarrow 60200L=6.0200\times 10^4L[/tex]

As, the decimal point is shifting to left side, thus the power of 10 is positive.

Hence, the correct answer is, [tex]6.0200\times 10^4L[/tex]

(b) As we are given the 4520 J in standard notation.

Now converting this into scientific notation, we get:

[tex]\Rightarrow 4520J=4.520\times 10^3J[/tex]

As, the decimal point is shifting to left side, thus the power of 10 is positive.

Hence, the correct answer is, [tex]4.520\times 10^3J[/tex]

(c) As we are given the 0.00600 mg in standard notation.

Now converting this into scientific notation, we get:

[tex]\Rightarrow 0.00600mg=6.00\times 10^{-3}mg[/tex]

As, the decimal point is shifting to right side, thus the power of 10 is negative.

Hence, the correct answer is, [tex]6.00\times 10^{-3}mg[/tex]

(d) As we are given the 0.01023 km in standard notation.

Now converting this into scientific notation, we get:

[tex]\Rightarrow 0.01023km=1.023\times 10^{-2}km[/tex]

As, the decimal point is shifting to right side, thus the power of 10 is negative.

Hence, the correct answer is, [tex]1.023\times 10^{-2}km[/tex]

(e) As we are given the 80.70 mL in standard notation.

Now converting this into scientific notation, we get:

[tex]\Rightarrow 80.70mL=8.070\times 10^1mL[/tex]

As, the decimal point is shifting to left side, thus the power of 10 is positive.

Hence, the correct answer is, [tex]8.070\times 10^1mL[/tex]

Given these reactions, where X represents a generic metal or metalloid 1 ) H 2 ( g ) + 1 2 O 2 ( g ) ⟶ H 2 O ( g ) Δ H 1 = − 241.8 kJ 2 ) X ( s ) + 2 Cl 2 ( g ) ⟶ XCl 4 ( s ) Δ H 2 = + 361.7 kJ 3 ) 1 2 H 2 ( g ) + 1 2 Cl 2 ( g ) ⟶ HCl ( g ) Δ H 3 = − 92.3 kJ 4 ) X ( s ) + O 2 ( g ) ⟶ XO 2 ( s ) Δ H 4 = − 607.9 kJ 5 ) H 2 O ( g ) ⟶ H 2 O ( l ) Δ H 5 = − 44.0 kJ what is the enthalpy, Δ H , for this reaction? XCl 4 ( s ) + 2 H 2 O ( l ) ⟶ XO 2 ( s ) + 4 HCl ( g )

Answers

Answer:

-767,2kJ

Explanation:

It is possible to sum enthalpies of half-reactions to obtain the enthalpy of a global reaction using Hess's law. For the reactions:

1) H₂(g) + ¹/₂O₂(g) ⟶ H₂O(g) ΔH₁= −241.8 kJ

2) X(s) + 2Cl₂(g) ⟶ XCl₄(s) ΔH₂= +361.7 kJ

3) ¹/₂H₂(g) + ¹/₂Cl₂(g) ⟶ HCl (g) ΔH₃= −92.3 kJ

4) X(s) + O₂(g) ⟶ XO₂(s) ΔH₄= − 607.9 kJ

5) H₂O(g) ⟶ H₂O(l) ΔH₅= − 44.0 kJ

The sum of (4) - (2) produce:

6) XCl₄(s) + O₂(g) ⟶ XO₂(s) + 2Cl₂(g) ΔH₆ = ΔH₄ - ΔH₂ = -969,6 kJ

(6) + 4×(3):

7) XCl₄(s) + 2H₂(g) + O₂(g) ⟶ XO₂(s) + 4HCl(g) ΔH₇ = ΔH₆ + 4ΔH₃= -1338,8 kJ

(7) - 2×(1):

8) XCl₄(s) + 2H₂O(g) ⟶ XO₂(s) + 4HCl(g) ΔH₈ = ΔH₇ - 2ΔH₁= -855,2kJ

(8) - 2×(5):

9) XCl₄(s) + 2H₂O(l) ⟶ XO₂(s) + 4HCl(g) ΔH₉ = ΔH₈ - 2ΔH₅= -767,2kJ

I hope it helps!

Final answer:

To calculate the enthalpy change for the reaction XCl4 (s) + 2 H2O (l) ⟶ XO2 (s) + 4 HCl (g), we can use Hess's law and the enthalpy values of the given reactions.

Explanation:

The enthalpy change for the reaction XCl4 (s) + 2 H2O (l) ⟶ XO2 (s) + 4 HCl (g) can be calculated using Hess's law and the enthalpy values of the given reactions.

To represent the desired reaction, we can combine reactions 2, 3, 4, and 5 as follows:

X (s) + 2 Cl2 (g) ⟶ XCl4 (s) [multiply this reaction by 2] 1/2 H2 (g) + 1/2 Cl2 (g) ⟶ HCl (g) [multiply this reaction by 4] X (s) + O2 (g) ⟶ XO2 (s) [multiply this reaction by 2] H2 (g) + 1/2 O2 (g) ⟶ H2O (l)

By summing these equations, we get the desired equation:

XCl4 (s) + 2 H2O (l) ⟶ XO2 (s) + 4 HCl (g)

--

The enthalpy change for the reaction is ΔH = ΔH2 + ΔH3 + ΔH4 + ΔH5.

For many purposes we can treat propane as an ideal gas at temperatures above its boiling point of . Suppose the temperature of a sample of propane gas is raised from ⁢ to , and at the same time the pressure is changed. If the initial pressure was and the volume increased by , what is the final pressure? Round your answer to the correct number of significant digits.

Answers

Answer: (This question is missing some values).

The  combined gas law is used to determine the change in volume, pressure and temperature of gases. It states that the ratio between the pressure-volume product and temperature is a constant.

Mathematically, P1V1/T1 = P2V2/T2, where P1 and P2 are the initial and final pressures, V1 and V2 are the initial and final volumes, T1 and T2 are the initial and final temperatures in kelvin.

Explanation:

The boiling point of propane is -42°C.

Assuming the initial and final temperatures are 10°C and 25°C respectively; the volume increased by 20%; if the initial pressure = 1atm, final pressure can be found using the equation P1V1/T1 = P2V2/T2.

P1 = 1atm, P2 = ?, V1 = V, V2 = 0.2V, T1 = 10 + 273K = 283K, T2 = 25 + 273K = 298K.

Making P2 subject of formula, P2 = P1V1T2/V2T1

P2 = 1 * V *298/(0.2 V * 283)

P2 = 5.2atm

Answer:

The equation you should use is:

Meaning of the initials of the equation:

INITIAL PRESSURE (P1)

FINAL PRESSURE (P2)

INITIAL VOLUME (V1)

FINAL VOLUME (V2)

FINAL TEMPERATURE (T2)

INITIAL TEMPERATURE (T1)

then the final equation would be:

(P1XV1) / T1 = (P2XV2) / T2

Explanation:

This equation is due to the fact that the gas is considered to be an ideal gas, so when behaving as such the values of "n" which is the number of moles is the same in the initial and final stage as the constant

"R" that has a value of 0.082 (with their respective units) both at the end and at the beginning of the reaction.

By not varying these components of the equation it is unnecessary to put them, since they would cancel themselves.

In the equation we mentioned before, it is necessary that if you want to know the final pressure, that is, P2, you have to clear it, considering that the final equation for this specific exercise is:

P2 = (P1XV1XT2) / V2

Which has not been suggested as a reasonably practical way to store large amounts of hydrogen in relatively small spaces for its use as a fuel?


A. Liquefy hydrogen under pressure and store it much as we do with liquefied natural gas today.


B. Absorb hydrogen onto activated charcoal; then heat the mixture to release the hydrogen.


C. Store it in the form of ionic metal hydrides, such as LiH, which release hydrogen gas when they react with water.


D. Encapsulate hydrogen molecules in fullerene molecules (large, carbon-based molecules that can act like cages) that may be heated later to release the hydrogen.

Answers

Answer: A. Liquefy hydrogen under pressure and store it much as we do with liquefied natural gas today.

Explanation:

Current Hydrogen storage methods fall into one of two technologies;

physical storage where compressed hydrogen gas is stored under pressure or as a liquid; and chemical storage, where the hydrogen is bonded with another material to form a hydride and released through a chemical reaction.

Physical storage solutions are commonly used technologies but are problematic when looking at using hydrogen to fuel vehicles. Compressed hydrogen gas needs to be stored under high pressure and  requires large and heavy tanks. Also, liquid hydrogen boils at -253°C (-423°F) so it needs to be stored cryogenically with heavy insulation and actually contains less hydrogen compared with the same volume of gasoline.  

Chemical storage methods allow hydrogen to be stored at much lower pressures and offer high storage performance due to the strong binding of hydrogen and the high storage densities. They also occupy relatively smaller spaces than either compressed hydrogen gas or liquified hydrogen. A large number of chemical storage systems are under investigation, which involve hydrolysis reactions, hydrogenation/dehydrogenation reactions, ammonia borane and other boron hydrides, ammonia, and alane etc.

Other practical storage methods being researched that focuses on storing hydrogen as a lightweight, compact energy carrier for mobile applications include;

Metal hydrides  e.g. LiHNanostructured metal hydrides Non-metal hydrides Carbohydrates Synthesized hydrocarbons Aluminum Liquid organic hydrogen carriers (LOHC) Encapsulation , e.t.c.

The list that correctly indicates the order of metallic character is __________.

A) B > N > C
B) F > Cl > S
C) Si > P > S
D) P > S > Se
E) Na > K > Rb

Answers

Answer:

C) Si > P > S .

Explanation:

In the Periodic Table, the metallic character increases from right to left and from top to bottom.

The list that correctly indicates the order of metallic character is  

A) B > N > C . NO. C is in Group 14 and N is in Group 15.

B) F > Cl > S . NO. F and Cl are in Group 17 and S is in Group 16.

C) Si > P > S . YES. Si is in Group 14, P is in Group 15 and S is in Group 16.

D) P > S > Se. NO. Se is below S in the Group 16.

E) Na > K > Rb. NO. Na is above K, which is above Rb in Group 1.

The ozonization of pentene in carbon tetrachloride solution at 25 o C5H10 + O3 C5H10O3 is first order in C5H10 and first order in O3.

1.Complete the rate law for this reaction in the box below.
Use the form k[A]m[B]n... , where '1' is understood for m, n ...(don't enter 1) and concentrations taken to the zero power do not appear.

Rate =

2.In an experiment to determine the rate law, the rate of the reaction was determined to be 649 Ms-1 when [C5H10] = 0.128 M and [O3] = 4.41E-2 M. From this experiment, the rate constant is ______M-1s-1.

Answers

1. The rate law is Rate = k[C5H10][O3].

2. The rate constant is 1.24E6 M-1s-1.

1. The rate law for the ozonization of pentene in carbon tetrachloride solution at 25 o C5H10 + O3 C5H10O3 is first order in C5H10 and first order in O3. Therefore, the rate law can be written as:

Rate = k[C5H10][O3]

2. The rate constant can be calculated using the following equation:

k = Rate / [C5H10][O3]

Substituting the known values into the equation above, we get the following:

k = 649 Ms-1 / 0.128 M * 4.41E-2 M

k = 1.24E6 M-1s-1

Therefore, the rate constant for the ozonization of pentene in carbon tetrachloride solution at 25 o C5H10 + O3 C5H10O3 is 1.24E6 M-1s-1.

Learn more about rate law here:

https://brainly.com/question/30461206

#SPJ6

A geological sample is found to have a Pb-206/U-238 mass ratio of 0.337/1.00. Assuming there was no Pb-206 present when the sample was formed, how old is it? The half-life of U-238 is 4.5 × 109 years.1.4 × 1010 years2.1 × 109 years7.3 × 1011 years7.1 × 109 years2.4 × 1010 years

Answers

Answer:

2.1x10⁹ years

Explanation:

U-238 is a radioactive substance, which decays in radioactive particles. It means that this substance will lose mass, and will form another compound, the Pb-206.

The time need for a compound loses half of its mass is called half-life, and knowing the initial mass (mi) and the final mass (m) the number of half-lives passed (n) can be found by:

m = mi/2ⁿ

The mass of Pb-206 will be the mass that was lost by U-238, so it will be mi - m. Thus, the mass ration can be expressed as:

(mi-m)/m = 0.337/1

mi - m = 0.337m

mi = 1.337m

Substituing mi in the expression of half-life:

m = 1.337m/2ⁿ

2ⁿ = 1.337m/m

2ⁿ = 1.337

ln(2ⁿ) = ln(1.337)

n*ln(2) = ln(1.337)

n = ln(1.337)/ln2

n = 0.4190

The time passed (t), or the age of the sample, is the half-life time multiplied by n:

t = 4.5x10⁹ * 0.4190

t = 1.88x10⁹ ≅ 2.1x10⁹ years

Final answer:

The age of a geological sample, given a Pb-206/U-238 mass ratio, can be calculated using the principles of radioactive decay and the known half-life of U-238. The formula t = (1/λ) × ln(1 + (Pb-206/U-238)) is used, where λ is the decay constant calculated as 0.693 / half-life.

Explanation:

To calculate the age of a geological sample based on the Pb-206/U-238 mass ratio and the half-life of U-238, we need to apply the principles of radioactive decay.

U-238 decays into Pb-206 with a half-life of 4.5 × 10⁹ years. The decay constant (λ) can be calculated, as λ = 0.693 / half-life. Assuming that there was no Pb-206 present when the sample was formed, we can derive the time passed since the rock formed using the formula t = (1/λ) × ln(1 + (Pb-206/U-238)).

Given that the Pb-206/U-238 mass ratio is 0.337/1.00, we would insert these values into the above formula to calculate the age. Without actual numeric calculation of this equation, we cannot provide a specific number among the options listed, but this is the method you would use to do so.

#SPJ3

Phenolphthalein has a pKa of 9.7 and is colorless in its acid form and pink in its basic form. calculate [In-}/{HIn} for the following pH

4.9

2.1

7.8

11.5

Answers

Answer:

1.58x10⁻⁵

2.51x10⁻⁸

0.0126

63.10

Explanation:

Phenolphthalein acts like a weak acid, so in aqueous solution, it has an acid form HIn, and the conjugate base In-, and the pH of it can be calculated by the Handerson-Halsebach equation:

pH = pKa + log[In-]/[HIn]

pKa = -logKa, and Ka is the equilibrium constant of the dissociation of the acid. [X] is the concentrantion of X. Thus,

i) pH = 4.9

4.9 = 9.7 + log[In-]/[HIn]

log[In-]/[HIn] = - 4.8

[In-]/[HIn] = [tex]10^{-4.8}[/tex]

[In-]/[HIn] = 1.58x10⁻⁵

ii) pH = 2.1

2.1 = 9.7 + log[In-]/[HIn]

log[In-]/[HIn] = -7.6

[In-]/[HIn] = [tex]10^{-7.6}[/tex]

[In-]/[HIn] = 2.51x10⁻⁸

iii) pH = 7.8

7.8 = 9.7 + log[In-]/[HIn]

log[In-]/[HIn] = -1.9

[In-]/[HIn] = [tex]10^{-1.9}[/tex]

[In-]/[HIn] = 0.0126

iv) pH = 11.5

11.5 = 9.7 + log[In-]/[HIn]

log[In-]/[HIn] = 1.8

[In-]/[HIn] = [tex]10^{1.8}[/tex]

[In-]/[HIn] = 63.10

The target diol is synthesized in one step from 1-methylcyclopentene, but your lab partner exhausted the supply of that alkene. Fortunately, you have plenty of isomers (C6H10) on hand from which to synthesize 1-methylcyclopentene and, ultimately, the diol. Provide the missing reagents and organic structures needed to most efficiently produce the target product.

Answers

Answer:

The reagents are [tex]CH_{3}CH_{3}O^{-},OsO_{4},NaHSO_{3}and H_{2}O[/tex].

Explanation:

1-Methylenecyclopentene is treated with HBr form 1-bromo-1-methylcyclopentane, which is treated with strong base ethoxide ion and forms 1-methylcyclopent-1-ene.

This alkene is treated with osmium tetraoxide in the presence of sodium bisulfite to form target product.

The chemical reaction is as follows.

Final answer:

With the help of isomers of C6H10, such as cyclohexene, it's possible to synthesize 1-methylcyclopentene by methylation and subsequent dehydrohalogenation. Once 1-methylcyclopentene is produced, the diol can be synthesized via a dihydroxylation process involving an oxidizing agent.

Explanation:

The synthesis of the target diol from 1-methylcyclopentene can be achieved even if the starting alkene is not available by using isomers of C6H10. The first step involves synthesizing 1-methylcyclopentene from an appropriate isomer. For instance, cyclohexene, an isomer of C6H10, can be first transformed into 1-methylcyclohexene through an acid-catalyzed methylation reaction. To get 1-methylcyclopentene, a controlled elimination (dehydrohalogenation) step is necessary. This will produce the alkene with the double bond at the correct location. Once you have synthesized 1-methylcyclopentene, creating the diol is straightforward by applying the reaction conditions for dihydroxylation, which add a hydroxyl group to each carbon of the double bond.

Let's illustrate:

Start with cyclohexene (C6H10).Add HCl and CH3OH as reagents under acidic conditions to produce 1-methylcyclohexene.Heat this product with a strong base (e.g., KOH) to induce dehydrohalogenation and result in 1-methylcyclopentene.Finally, add an oxidizing agent (e.g., KMnO4) under acidic conditions to create the target diol.

Learn more about Organic Chemistry Synthesis here:

https://brainly.com/question/14917187

#SPJ11

1. The most useful ore of aluminum is bauxite, in which Al is present as hydrated oxides, Al2O3⋅xH2O The number of kilowatt-hours of electricity required to produce 4.00kg of aluminum from electrolysis of compounds from bauxite is ________ when the applied emf is 5.00V. 2. The most useful ore of aluminum is bauxite, in which Al is present as hydrated oxides, The number of kilowatt-hours of electricity required to produce of aluminum from electrolysis of compounds from bauxite is ________ when the applied emf is a. 59.6 b. 0.0168 c. 0.0596 d. 19.9 e. 39.7

Answers

*Answer:

Option A: 59.6

Explanation:

Step 1: Data given

Mass of aluminium = 4.00 kg

The applied emf = 5.00 V

watts = volts * amperes

Step 2: Calculate amperes

equivalent mass of aluminum = 27 / 3 = 9  

mass of deposit = (equivalent mass x amperes x seconds) / 96500

4000 grams = (9* amperes * seconds) / 96500

amperes * seconds = 42888888.9

1 hour = 3600 seconds

amperes * hours = 42888888.9 / 3600 = 11913.6

amperes = 11913.6 / hours

Step 3: Calculate kilowatts

watts = 5 * 11913.6 / hours

watts = 59568 (per hour)

kilowatts = 59.6 (per hour)

The number of kilowatt-hours of electricity required to produce 4.00kg of aluminum from electrolysis of compounds from bauxite is 59.6 kWh when the applied emf is 5.00V

A 150.0 mL solution of 2.888 M strontium nitrate is mixed with 200.0 mL of a 3.076 M sodium fluoride solution. Calculate the mass of the resulting strontium fluoride precipitate. mass: g Assuming complete precipitation, calculate the final concentration of each ion. If the ion is no longer in solution, enter a 0 for the concentration. [ Na + ] = M [ NO − 3 ] = M [ Sr 2 + ] = M [ F − ] = M

Answers

Answer:

Mass SrF2 produced = 38.63 g SrF2 produced

[Na^+]:  = 1.758 M

[NO3^-]:  = 1.238 M

[Sr^2+] = 0.3589 M

[F^-] = 2.36*10^-5 M

Explanation:

Step 1: Data given

Volume of 2.888M strontium nitrate = 150.0 mL = 0.150 L

Volume of 3.076 M sodium fluoride = 200.0 mL = 0.200 L

Step 2 : The balanced equation

Sr(NO3)2(aq) + 2NaF(aq) → SrF2(s) + 2NaNO3(aq) → Sr2+ + 2F- + 2

Step 3: Calculate moles strontium nitrate

Moles Sr(NO3)2 = Molarity * volume  

Moles Sr(NO3)2 = 2.888 M * 0.150 L

Moles Sr(NO3)2 = 0.4332 moles

Step 4: Calculate moles NaF

Moles NaF = 3.076 M * 0.200 L

Moles NaF = 0.6152 moles

It takes 2 moles F^- to precipitate 1 mole Sr^2+, so F^- is limiting.

Step 5: Calculate limiting reactant

For 1 mol of Sr(NO3)2 we need 2 moles of NaF to produce 1 mol of SrF2 and 2 moles of NaNO3

NaF is the limiting reactant. It will completely be consumed (0.6152 moles).

Sr(NO3)2 is in excess. There will react 0.6152/2 = 0.3076 moles

Moles Sr^2+ precipitated by F^- = 0.3076

There will remain 0.4332 - 0.3076 = 0.1256 moles of Sr(NO3)2

Moles Sr^2+ no precipitated (left over) = 0.1256 moles

Step 6: Calculate moles SrF2  

For 1 mol of Sr(NO3)2 we need 2 moles of NaF to produce 1 mol of SrF2 and 2 moles of NaNO3

For 0.6152 moles NaF we have 0.6152/2 = 0.3076 moles of SrF2

Mass SrF2 produced:  0.3076 mol * 125.6 g/mol = 38.63 g SrF2 produced

Step 7: Calculate concentration of [Na+] and [NO3-]

Since both Na^+ and NO3^- are spectator ions, and the final volume is 150 ml + 200 ml = 350 ml (0.350 L), the concentrations of Na^+ and NO3^- can be calculated as follows:

[Na^+]:  (200 ml)(3.076 M) = (350 ml)(x M) and x = 1.758 M

[NO3^-]:  (150 ml)(2.888 M)(2) = (350 ml)(x M) = 1.238 M

Step 8: Calculate [Sr^2+] and [F^-]

[Sr^2+] = 0.1256 moles/0.350 L = 0.3589 M

To find [F^-], one needs the Ksp for SrF2.  There are several values listed in the literature. I am using a value of 2x10^-10.

SrF2(s) <==> Sr^2+(aq) + 2F^-(aq)

Ksp = [Sr^2+][F^-]²

2x10^-10 = (0.3589)(x)²

x² = 5.57*10^-10

x = [F^-] = 2.36*10^-5 M

The mass of SrF2 precipitate formed in the reaction is 38.69 g

We have to first write down the balanced reaction equation as follows;

Sr(NO3)2(aq) + 2NaF(aq)------> SrF2(s) + 2NaNO3(aq)

Next, we obtain the number of moles of each reactant;

Amount of Sr(NO3)2 = 150.0/1000 × 2.888  = 0.433 mols of Sr(NO3)2

Amount of NaF = 200.0/1000 × 3.076 = 0.615 moles of NaF

We have to obtain the limiting reactant. This is the reactant that yields the lowest number of moles of product.

For Sr(NO3)2:

1 mole of Sr(NO3)2 yields 1 mole of SrF2

0.433 mols of Sr(NO3)2 yields 0.433 mols of SrF2

For NaF;

2 moles of NaF yields  1 mole of SrF2

0.615 moles of NaF yields 0.615 × 1/2 = 0.308 moles of SrF2

Hence NaF is the limiting reactant.

Mass of  SrF2 formed =  0.308 moles of SrF2 × 125.62 g/mol = 38.69 g

Learn more: https://brainly.com/question/9743981

2. Perception:
a. is faulty.
b. is not always accurate.
c. does not always reflect reality.
d. All of these choices.

Answers

Perception is an accurate but imperfect process, influenced by expectations, emotions, and selective attention, which can lead to illusions and misinterpretations of the environment.

Understanding Perception

Perception is the process by which we interpret the information our senses provide. While it is a very accurate system, it is not infallible. Our expectations and emotions can influence our perception, sometimes leading to illusions or inaccurate judgments. For instance, when confronted with an optical illusion, our understanding of size, distance, and color might be challenged, resulting in a misinterpreted reality.

Expectations play a significant role in shaping perception. For example, if someone expects to see a certain outcome, they might unconsciously ignore evidence that contradicts their expectation. This is evident in situations where stereotypes or generalizations are held about people or situations, often resulting in biased communication.

Another aspect is selective attention; we tend to perceive and interpret things that are in line with our focus. If our attention is elsewhere, we might not perceive something obvious. Further, perception is a key component during arguments, where people defend their subjective reality instead of considering the objective external environment.

In summary, perception is a complex process influenced by individual biases and attention, often resulting in a personally constructed reality rather than an accurate reflection of the environment.

The half life for the decay of carbon-14 is 5.73 x 10^3 years. Suppose the activity due to the radioactive decay of the carbon-14 in a tiny sample of an artifact made of wood from an archeological dig is measured to be 53.Bq. The activity in a similar-sized sample of fresh wood is measured to be 59.Bq.
1. Calculate the age of the artifact. Round your answer to 2 significant digits.

Answers

Final answer:

To find the age of the artifact using carbon-14 activity, we calculate the ratio of current activity to original activity, use the decay formula with the half-life of carbon-14, and solve for time, yielding an estimated age of approximately 888 years.

Explanation:

To calculate the age of the artifact based on its carbon-14 activity, we use the concept of radioactive decay and the half-life of carbon-14. The half-life is the time taken for half of the radioactive atoms in a sample to decay. In the case of carbon-14, its half-life is 5,730 years.

We start by finding the ratio of the current activity to the original activity.

Original activity (fresh wood) = 59 Bq

Current activity (artifact) = 53 Bq

Ratio (current/original) = 53 Bq / 59 Bq = 0.898

Next, we use the decay formula: N(t) = N0 × (1/2)(t/T), where:

N(t) is the remaining amount of substance after time t

N0 is the original amount of substance

T is the half-life of the substance

t is the time that has passed

Plugging in the values we know: 0.898 = (1/2)(t/5730)

To solve for t, we take the natural logarithm of both sides of the equation:

ln(0.898) = ln((1/2)(t/5730))
ln(0.898) = (t/5730) × ln(1/2)

After calculating:

t = 5730 × ln(0.898) / ln(1/2) = 5730 × -0.107 / -0.693
t ≈ 888 years (rounded to two significant digits)

Therefore, the age of the artifact is approximately 888 years old.

What is the half-life of A? What will the pressure, initially 32.1 kPa, at

(a) 10 s,
(b) 10 min after initiation of the reaction?

Answers

Answer:

a) 32.09 kPa

b) 32.09 kPa

Explanation:

Given data:

rate constant [tex]= 3.56\times 10^{-7} s^{-1}[/tex]

initial pressure is = 32.1 kPa

half life of A is calculated as

[tex]t_{1/2} = \frac{ln 2}{k}[/tex]

[tex]t_{1/2} = \frac{ln 2}{3.56\time 10^{-7}}[/tex]

[tex]t_{1/2} = = 1.956 \times 10^6 s[/tex]

for calculating pressure we have follwing expression

[tex]ln p = ln P_o - kt[/tex]

[tex]P =P_o e^{-kt}[/tex]

a) [tex]P = 32.1 e^{-3.56\times 10^{-7} \times 10} = 32.09 kPa[/tex]

b) [tex]P = 32.1 e^{-3.56\times 10^{-7} \times 10\times 60} = 32.09 kPa[/tex]

When a student mixes 50 mL of 1.0 M HCl and 50 mL of 1.0 M NaOH in a coffee-cup calorimeter, the temperature of the resultant solution increases from 21.0 °C to 27.5 °C. Calculate the enthalpy change for the reaction in kJ per mol of HCl, assuming that the calorimeter loses only a negligible quantity of heat. The total volume of the solution is 100 mL, its density is 1.0 g/mL, and its specific heat is 4.18 J/g*K.

Answers

Answer: 54.4 kJ/mol

Explanation:

First we have to calculate the moles of HCl and NaOH.

[tex]\text{Moles of HCl}=\text{Concentration of HCl}\times \text{Volume of solution}=1.0M\times 0.05=0.05mole[/tex]

[tex]\text{Moles of NaOH}=\text{Concentration of NaOH}\times \text{Volume of solution}=1.0\times 0.05L=0.05mole[/tex]

The balanced chemical reaction will be,

[tex]HCl+NaOH\rightarrow NaCl+H_2O[/tex]

From the balanced reaction we conclude that,

As, 1 mole of HCl neutralizes by 1 mole of NaOH

So, 0.05 mole of HCl neutralizes by 0.05 mole of NaOH

Thus, the number of neutralized moles = 0.05 mole

Now we have to calculate the mass of water:

As we know that the density of water is 1 g/ml. So, the mass of water will be:

The volume of water = [tex]50ml+50ml=100ml[/tex]

[tex]\text{Mass of water}=\text{Density of water}\times \text{Volume of water}=1g/ml\times 100ml=100g[/tex]

Now we have to calculate the heat absorbed during the reaction.

[tex]q=m\times c\times (T_{final}-T_{initial})[/tex]

where,

q = heat absorbed = ?

[tex]c[/tex] = specific heat of water = [tex]4.18J/g^oC[/tex]

m = mass of water = 100 g

[tex]T_{final}[/tex] = final temperature of water = [tex]27.5^0C[/tex]

[tex]T_{initial}[/tex] = initial temperature of metal = [tex]21.0^0C[/tex]

Now put all the given values in the above formula, we get:

[tex]q=100g\times 4.18J/g^oC\times (27.5-21.0)^0C[/tex]

[tex]q=2719.6J=2.72kJ[/tex]

Thus, the heat released during the neutralization = 2.72 KJ

Now we have to calculate the enthalpy of neutralization per mole of [tex]HCl[/tex]:

0.05 moles of [tex]HCl[/tex] releases heat = 2.72 KJ

1 mole of [tex]HCl[/tex] releases heat =[tex]\frac{2.72}{0.05}\times 1=54.4KJ[/tex]

Thus the enthalpy change for the reaction in kJ per mol of HCl is 54.4 kJ

Answer:

54.34 kJ/mol of HCl

Explanation:

The calorimeter is a device used to determine the heat that is lost or gained, by a reaction. When the temperature change without a phase change, the heat (Q) can be calculated by:

Q = m*c*ΔT

Where m is the mass of the solution, c is the specific heat of the solution, and ΔT is the temperature variation (final - initial). The mass of the solution is the density multiplied by the volume:

m = 1.0 g/mL * 100 mL = 100 g

The temperature variation in °C is equal to the temperature variation in K, thus:

Q = 100g * 4.18J/gK * (27.5 - 21.0)K

Q = 2717 J

Thus, the solution gained 2717 J of heat. The enthalpy is how much of this energy is inside the matter, thus, it is the heat divided by the number of moles of a substance.

The number of moles of HCl is the volume (50 mL = 0.05 L) multiplied by the concentration:

n = 0.05 L * 1.0 M = 0.05 mol

The enthalpy is the heat divided by the number of moles:

H = 2717/0.05

H = 54340 J/mol of HCl

H = 54.34 kJ/mol of HCl

Which of the slightly soluble salts below will be more soluble in acidic solution than in pure water?

a. Mg(OH)2
b. CaCO3
c. AgCl Mg(OH)2
d. only Mg(OH)2,
e. CaCO3, and
f. AgCl
g. CaCO3 only
h. both Mg(OH)2 and CaCO3

Answers

Answer:

h. both Mg(OH)₂ and CaCO₃

Explanation:

Let's consider the solution of Mg(OH)₂ according to the following equation:

Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)

In acidic solution, OH⁻ reacts with H⁺ to form H₂O.

OH⁻(aq) + H⁺(aq) ⇄ H₂O(l)

According to Le Chatelier's principle, since [OH⁻] decreases, the solution of Mg(OH)₂(s) shifts toward the right, increasing its solubility.

Let's consider the solution of CaCO₃ according to the following equation:

CaCO₃(s) ⇄ Ca²⁺(aq) + CO₃²⁻(aq)

In acidic solution, CO₃²⁻ reacts with H⁺ to form HCO₃⁻.

CO₃²⁻(aq) + H⁺(aq) ⇄ HCO₃⁻(aq)

According to Le Chatelier's principle, since [CO₃²⁻] decreases, the solution of CaCO₃(s) shifts toward the right, increasing its solubility.

Let's consider the solution of AgCl according to the following equation:

AgCl(s) ⇄ Ag⁺(aq) + Cl⁻(aq)

Cl⁻ does not react with H⁺ because it comes from a strong acid (HCl). Therefore, the solubility of AgCl(s) is not affected by the pH.

Final answer:

Mg(OH)₂ and CaCO₃ are more soluble in acidic solutions due to reactions with H+ ions that remove the OH- and CO₃²⁻ from the solution, driving the dissolution equilibrium forward.

Explanation:

The question asks which of the slightly soluble salts listed will be more soluble in acidic solution than in pure water. Specifically, salts like Mg(OH)₂ (magnesium hydroxide) and CaCO₃ (calcium carbonate) will be more soluble in an acidic solution. This is because the acid in the solution will react with the anionic part of the salt, which in the case of Mg(OH)2 is OH- and for CaCO₃ is CO₃²⁻. For example, in an acidic solution, H+ ions will react with OH- to form water, which effectively removes OH- from the solution and drives the dissolution equilibrium forward, increasing the solubility of Mg(OH)₂. Similarly, H+ ions will react with CO₃²⁻ to form HCO₃- (bicarbonate) or even further to H₂CO₃ (carbonic acid), which are more soluble than the carbonate ion, hence increasing the solubility of CaCO₃.

As for AgCl (silver chloride), it will also be more soluble in acidic solution because the chloride ion is not basic, and it does not react with H+ to form a weaker acid. Therefore, the correct answers that are more soluble in acidic solution than in pure water are Mg(OH)₂ and CaCO₃.

1.When HCl(aq) and NaOH(aq) are mixed in a beaker, the beaker feels warm to the touch. What is known about the enthalpy of this reaction?a. The reaction is exothermic.b. The reaction is endothermic.c. Heat is absorbed from the surroundings.d. \DeltaH is positive.Part B 2. Consider this combination reaction: 2Mg(s)+O2(g)→2MgO(s) ΔH=−1204 kJ What is the enthalpy for the decomposition of 1 mole of MgO(s) into Mg(s) and O2(g)? View Available Hint(s) A. -602 kJ/mol B. 602 kJ/mol C. -1204 kJ/mol D. 1204 kJ/mol Part C 3. The enthalpy for the formation of 1 mole of NH3(aq) is -80.29 kJ/mol. What is the enthapy for the formation of 3 moles of NH3(aq)? View Available Hint(s) The enthalpy for the formation of 1 mole of is -80.29 . What is the enthapy for the formation of 3 moles of ? A -83.29 kJ B. -518×103 kJ C. -240.87 kJ D. -26.76 kJ

Answers

Answer:

1. The correct answer is option a.

2. The correct answer is option B.

3. The correct answer is option C.

Explanation:

1. When acid reacts with base heat is generated along with formation of salt and water.

[tex]HCl+NaOH\rightarrow NaCl+H_2O,\Delta H=Negative[/tex]

Those reaction in which heat released as a product is called exothermic reaction.Exothermic reaction have negative value of enthalpy of reaction

2. [tex]2Mg(s)+O_2(g)→2MgO(s), \Delta H=-1204 kJ[/tex]

If we reveres the equation we  will have the reaction in which MgO is getting decomposed into Mg and oxygen gas.

[tex]2MgO\rightarrow 2Mg+O_2(g),\Delta H=1204 kJ[/tex]

Divide the whole equation by 2.

[tex]MgO\rightarrow Mg+\frac{1}{2}O_2(g),\Delta H=602 kJ[/tex]

602 kJ is the enthalpy for the decomposition of 1 mole of MgO(s).

3.

The enthalpy for the formation of 1 mole of liquid ammonia = -80.29 kJ/mol

So, enthalpy of formation of 3 moles of  liquid ammonia :

[tex]3 mol\times (-80.29 kJ/mol)=-240.87 kJ[/tex]

-240.87 kJ is the enthapy for the formation of 3 moles of liquid ammonia.

Other Questions
how does popular opinion shape political policies? Mccarthyism Marcia proposed the concept of _____ to describe a person's position in the development of identity. Type the correct answer in the box.The park district is paying to enlarge the area of a square-shaped dock at a local lake. The area of the dock will increase by 16 square feet.Complete the equation below that can be used to find the area, x, of the original dock if the side length of the new dock is 20 feet.\ CERTs should attempt to suppress only fires that are smaller than the size of a: A. Wastepaper can B. Pickup truck C. Wood shed D. Couch or sofa Electrically charged sunspot gases which escape the sun's chromosphere and enter the earth's atmosphere near the magnetic north pole cause the _______. Compared to consumers, producers will lose the lesser amount of surplus from a tax if: Which of the following statements about olfactory receptors is false? Select one: a. They are bulb-like structures at the tip of the frontal lobe where the olfactory nerves begin. b. They are cells. c. They are located in a mucous membrane at the top of the nose. d. They have small, hair-like extensions. Some sources report that the weights of full-term newborn babies in a certain town have a mean of 7 pounds and a standard deviation of 1.2 pounds and are normally distributed.a. What is the probability that one newborn baby will have a weight within 1.2 pounds of the meanlong dashthat is, between 5.8 and 8.2 pounds, or within one standard deviation of the mean?b. What is the probability that the average of nine babies' weights will be within 1.2 pounds of the mean; will be between 5.8 and 8.2 pounds?c. Explain the difference between (a) and (b). Which of the following supports the claim that the atom is like a solid positive cookie with negative electrons embedded within it? (This model is known as the Plum Pudding Model of the atom, and is illustrated to the right).a. Law of Constant Composition, Law of Multiple Proportions, Law of Conservation of Mass Alpha particles are scattered at a variety of angles (over 90 degrees) when bombarded at gold foil.b. When light from hydrogen emissions passes through a diffracting grating, there are distinct bands of color.c. The Cathode Ray Tube experiment, in which the ray was attracted to the south pole of the magnet. When walking or jogging on the shoulder of a roadway that does not have sidewalks and that is not within a business or residential district, a pedestrian must try to stay: Fast Corporation recently borrowed $600,000 from its bank at a simple interest rate of 14 percent. The loan is for 10 months. The loan agreement requires interest to be added to the amount borrowed and the total amount to be repaid in monthly installments. What is the loan's monthly payment? Which expression is equivalent to StartFraction (5 a b) cubed Over 30 a Superscript negative 6 Baseline b Superscript negative 7 Baseline EndFraction? Assume a not-equals 0, b not-equals 0. University students were observed to pull harder on a rope when they thought they were pulling alone than when they thought three others were pulling with them on the same rope. This best illustrates: Find the sum of -2 and -5. Then, in two or more complete sentences, explain the steps you used to add the mixed numbers.please help Which of the following is/are good example(s) of data collection strategies for parents?A) Parents complete a log book entry when they implement intervention and provide a brief narrative description of their child's performance.B) Parents record the frequency of a specific behavior by recording a tally on a piece of paper if the child demonstrates the target behavior.C) Parents record whether a specific behavior occurred at least one time by recording a tally on a piece of paper if the child demonstrates the target behavior.D) Parents provide in depth information about a target behavior by recording whether his/her response was correct, what prompt the child needed to complete a task, and how the child was reinforced. 20 pts and brainiest if correct. Please and Thank You Research suggests that older adults require ______ the current RDA for protein for adults.1. more than2. less than3. the same amount as Claire is the owner and chef at Vanilla and Sugar, a cafe that also offers a range of baked products. Claire employs two people who help her with various tasks at the cafe. At Vanilla and Sugar, tasks tend to be distributed among the two employees in an informal manner rather than each person developing a narrow area of specialization. Vanilla and Sugar is most likely to have a _____ structure 2. Which of the following represents the judicial philosophy of deciding cases based uponprecedent and the original intent of the Constitution?judicial activismjudicial powerjudicial restraintjudicial review The software team of a company is working on a project. The project involves many computing systems working together on disjointed tasks towards a single goal. What form of computing would the project be using? A. mobile computing B. grid computing C. cloud computing D. green computing Steam Workshop Downloader