Answer:
26.0 g/mol is the molar mass of the gas
Explanation:
We have to combine density data with the Ideal Gases Law equation to solve this:
P . V = n . R .T
Let's convert the pressure mmHg to atm by a rule of three:
760 mmHg ____ 1 atm
752 mmHg ____ (752 . 1)/760 = 0.989 atm
In density we know that 1 L, occupies 1.053 grams of gas, but we don't know the moles.
Moles = Mass / molar mass.
We can replace density data as this in the equation:
0.989 atm . 1L = (1.053 g / x ) . 0.082 L.atm/mol.K . 298K
(0.989 atm . 1L) / (0.082 L.atm/mol.K . 298K) = 1.053 g / x
0.0405 mol = 1.053 g / x
x = 1.053 g / 0.0405 mol = 26 g/mol
A certain ionic compound X has a solubility in water of 40.3 g/L at 20. degrees C. Calculate the mass X of required to prepare 500. mL of a saturated solution of X in water at this temperature. Be sure your answer has the correct unit symbol and 3 significant digits.
Answer:
20.1 g
Explanation:
The solubility indicates how much of the solute the solvent can dissolve. A solution is saturated when the solvent dissolved the maximum that it can do, so, if more solute is added, it will precipitate. The solubility varies with the temperature. Generally, it increases when the temperature increases.
So, if the solubility is 40.3 g/L, and the volume is 500 mL = 0.5 L, the mass of the solute is:
40.3 g/L = m/V
40.3 g/L = m/0.5L
m = 40.3 g/L * 0.5L
m = 20.1 g
The solubility value indicates how much of compound X can be dissolved in water at 20°C. Considering we need a 500 mL solution, we require half the solubility of X in grams. Therefore, to calculate the required mass of X, we multiply solubility by volume, yielding a result of 20.15 g.
Explanation:To calculate the mass of compound X required to prepare a saturated solution of 500 mL, we first need to understand the solubility value provided. The solubility of X is given as 40.3 g/L at 20°C, meaning that 1 L of water can dissolve 40.3 g of X at this temperature.
Since we need only 500 mL (or 0.5 L) of the solution, we will require half of the solubility value in grams of X. Therefore, by simple multiplication, we get:
X mass = Solubility * Volume
= 40.3 g/L * 0.5 L = 20.15 g
So, 20.15 g of compound X is needed for a saturated solution of 500 mL at 20°C.
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The proper solvent choice is crucial for effective recrystallization. What are the features of a good recrystallization solvent? Select all that apply.
a. The solvent should dissolve a moderate quantity of the target substance near its boiling point but only a small quantity near 0 °C.
b. The solvent should not react with the target substance.
c. The crude compound should be soluble in this solvent at room temperature.
d. The solvent should be easily removed from the purified product.
e. The solvent should have a high boiling point.
Answer:
a, b and d
Explanation:
Proper Solvent choice is very important for effective recrystallization.
Therefore, features of a good solvent are.
a. The solvent should dissolve a moderate quantity of the target substance near its boiling point but only.
b. The solvent should not react with the target substance.
d. The solvent should be easily removed from the purified product.
options c and d are not a property of good solvent.
Consider this reaction occurring at 298 K:
N2O(g) + NO2(g) ⇆ 3 NO(g)
If a reaction mixture contains only N2O and NO2 at partial pressures of 1.0 atm each, the reaction will be spontaneous until some NO forms in the mixture.
What maximum partial pressure of NO builds up before the reaction ceases to be spontaneous?
The question is incomplete, here is the complete question:
Consider this reaction occurring at 298 K:
[tex]N_2O(g)+NO_2(g)\rightleftharpoons 3NO(g)[/tex]
If a reaction mixture contains only [tex]N_2O\text{ and }NO_2[/tex] at partial pressures of 1.0 atm each, the reaction will be spontaneous until some NO forms in the mixture.
What maximum partial pressure of NO builds up before the reaction ceases to be spontaneous. Given that: [tex]\Delta G^o_{rxn}=107.8kJ/mol[/tex]
Answer: The maximum partial pressure of NO will be [tex]5.01\times 10^{-7}atm[/tex]
Explanation:
For the given chemical equation:
[tex]N_2O(g)+NO_2(g)\rightleftharpoons 3NO(g)[/tex]
The expression of [tex]K_p[/tex] for above equation follows:
[tex]K_p=\frac{p_{NO}^3}{p_{N_2O}\times p_{NO_2}}[/tex]
When the reaction ceases to be spontaneous, the [tex]\Delta G=0[/tex] (at equilibrium)
Relation between standard Gibbs free energy and equilibrium constant follows:
[tex]\Delta G=\Delta G^o+2.303RT\log K_p[/tex]
where,
[tex]\Delta G^o[/tex] = Standard Gibbs free energy = 107.8 kJ/mol = 107800 J/mol (Conversion factor: 1 kJ = 1000 J )
R = Gas constant = [tex]8.314J/K mol[/tex]
T = temperature = 298 K
[tex]p_{N_2O}=1.00atm[/tex]
[tex]p_{NO_2}=1.00atm[/tex]
Putting values in above equation, we get:
[tex]0=107800J/mol+(2.303\times 8.314J/Kmol)\times 298K\times \log (\frac{p_{NO}^3}{1.00\times 1.00})[/tex]
[tex]-107800=5705.85\times \log (\frac{p_{NO}^3}{1.00\times 1.00})\\\\-18.893=\log (p_{NO}^3)-\log (1.00)\\\\-18.893=3\log (p_{NO})\\\\\log (p_{NO})=-6.30\\\\p_{NO}=10^{-6.30}=5.01\times 10^{-7}atm[/tex]
Hence, the maximum partial pressure of NO will be [tex]5.01\times 10^{-7}atm[/tex]
If a substance has a density of 2.82 g/mL, what will be the volume (in mL) of a 5.71 g sample
Answer: 2.02mL
Explanation:
Density = 2.82 g/mL
Mass = 5.71 g
Volume =?
Density = Mass /volume
2.82 = 5.71 / Volume
Volume = 5.71 / 2.82
Volume = 2.02mL
Given one mole of each substance, which of the following will produce the FEWEST particles in aqueous solution? 1. sodium nitrate 2. CH2Cl2 3. K2SO4 4. sodium phosphate
Answer: The substance that produces fewest particles is [tex]CH_2Cl_2[/tex]
Explanation:
Ionization reaction is defined as the reaction in which an ionic compound dissociates into its ions when dissolved in aqueous solution.
Covalent compounds do not dissociate into ions when dissolved in aqueous solution.
For the given options:
Option 1: Sodium nitrateThe chemical formula of sodium nitrate is [tex]NaNO_3[/tex]
The ionization reaction for the given compound follows:
[tex]NaNO_3(aq.)\rightarrow Na^+(aq.)+NO_3^-(aq.)[/tex]
This produces in total of 2 ions.
Option 2: [tex]CH_2Cl_2[/tex]The given compound is a covalent compound and do not dissociate into its ions. It remains as such as a single unit.
Option 3: [tex]K_2SO_4[/tex]The chemical name for the given compound is potassium sulfate.
The ionization reaction for the given compound follows:
[tex]K_2SO_4(aq.)\rightarrow 2K^+(aq.)+SO_4^{2-}(aq.)[/tex]
This produces in total of 3 ions.
Option 4: Sodium phosphateThe chemical formula of sodium phosphate is [tex]Na_3PO_4[/tex]
The ionization reaction for the given compound follows:
[tex]Na_3PO_4(aq.)\rightarrow 3Na^+(aq.)+PO_4^{3-}(aq.)[/tex]
This produces in total of 4 ions.
Hence, the substance that produces fewest particles is [tex]CH_2Cl_2[/tex]
When a 0.089M aqueous solution of a certain acid is prepared, the acid is 12.% dissociated. Calculate the pH of the solution. Round your answer to 2 decimal places.
Answer:
pH = 1.98
Explanation:
Given a general acid dissociation:
HA + H₂O ⇆ H₃O⁺ + A⁻
The pH is -log[ H₃O⁺ ]
Therefore we need to determine [ H₃O⁺ ] to answer this question, and we should use the data of % dissociation of the acid.
Percent dissociation is
% dissociation = [ H₃O⁺ ] / [ HA ]₀ x 100
where [ HA ]₀ is the original acid concentration, so we can calculate [ H₃O⁺ ] , and then the pH.
12 = [ H₃O⁺ ] /0.089 M ⇒ [ H₃O⁺ ] = (12 x 0.089 /100) M
= 1.07 x 10⁻² M
and pH = - log ( 1.07 x 10⁻² ) = 1.98
To determine the pH of a 0.089M solution of an acid that is 12% dissociated, we first calculate the hydronium ion concentration and then use the formula for pH. After calculation, the pH is found to be 2.97.
Explanation:To calculate the pH of the solution where the acid is 12% dissociated, we first need to determine the concentration of hydronium ions ([H+]) in the solution.
Given a 0.089M solution of an acid that is 12% dissociated, the concentration of dissociated hydronium ions is:
This concentration has three significant figures. Using the formula for pH which is:
The pH is then calculated as:
pH = -log(0.01068) = 2.97
The result is in the acidic pH range, and it has been rounded to two decimal places to match the number of significant figures from the initial concentration given.
Two beakers contain clear. colorless liquids. When the contents of the beakers are mixed a white solid is formed, (a) Is this an example of a chemical or a physical change? (b) What would be the most convenient way to separate the newly formed white solid from the liquid mixture-filtration, distillation, or chromatography.
Answer:
1) chemical change
2) filtration
Explanation:
A chemical change involves the formation of a new substance. In this case, the pure white solid formed is an entirely new substance, with a different chemical identity from those of the two solutions mixed to form it. The new solid is a precipitate. Precipitates are easily separated by filtration of the reaction mixture. Another name for chemical change is chemical reaction.
1) This is an example of chemical change.
2) The most convenient way to separate the newly formed white solid from the liquid mixture is filtration
What is a Chemical change?A chemical change involves the formation of a new substance. In this case, the pure white solid formed is an entirely new substance, with a different chemical identity from those of the two solutions mixed to form it. The new solid is a precipitate. Precipitates are easily separated by filtration of the reaction mixture. Another name for chemical change is chemical reaction.
The most convenient way to separate the newly formed white solid from the liquid mixture is filtration since precipitates are formed.
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Which of these is a general feature of the lipid bilayer in all biological membranes?
a) individual lipid molecules are free to diffuse laterally in the surface of the bilayer
b) individual lipid molecules in one monolayer of the bilayer readily diffuse (flip-flop) to the other monolayer.
c) polar, but uncharged, compounds readily diffuse across the bilayer
d) the bilayer is stabilized by covalent bonds between neighboring phospholipid molecules.
e) the polar head groups face inward toward the inside of the bilayer
A
Individual lipid molecules are free to diffuse laterally in the surface of the bilayer is a general feature of the lipid bilayer in all biological membranes
Explanation:
The inside of the bilipid layer of the cell membrane of cells is made of fatty acid chains and cholesterol which are nonpolar molecules. they are sandwiched between the polar (glycerol) ends of the chains because they are hydrophobic and cannot interact with the ‘watery’ extracellular fluids. Non-polar molecules like lipids can easily diffuse laterally, within this lipid layers of the membrane because non-polar molecules interact well with other nonpolar molecules.
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cortisol is a steroid hormone involved in protein synthesis. what is its molecular formula
Answer:
C21H30O5
Explanation:
Cortisol with molecular formula C21H30O5 is a steroid hormone released by adrenal glands, it is involved in protein synthesis and can also help to control blood sugar level .
A chemist prepares a solution of mercury(II) iodide by weighing out of mercury(II) iodide into a volumetric flask and filling the flask to the mark with water. Calculate the concentration in of the chemist's mercury(II) iodide solution. Be sure your answer has the correct number of significant digits.
The question is incomplete, here is the complete question:
A chemist prepares a solution of mercury(II) iodide [tex](HgI_2)[/tex] by measuring out 0.0122 µmol of mercury(II) iodide into a 400 mL volumetric flask and filling the flask to the mark with water.
Calculate the concentration in mol/L of the chemist's mercury(II) iodide solution. Be sure your answer has the correct number of significant digits.
Answer: The molarity of chemist's mercury (II) iodide solution is [tex]3.05\times 10^{-8}mol/L[/tex]
Explanation:
To calculate the molarity of solution, we use the equation:
[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}[/tex]
We are given:
Moles of mercury (II) iodide = [tex]0.0122\mu mol=0.0122\times 10^{-6}mol[/tex] (Conversion factor: [tex]1mol=10^6\mu mol[/tex] )
Volume of solution = 400. mL
Putting values in above equation, we get:
[tex]\text{Molarity of }HgI_2=\frac{0.0122\times 10^{-6}\times 1000}{400.}\\\\\text{Molarity of }HgI_2=3.05\times 10^{-8}mol/L[/tex]
Hence, the molarity of chemist's mercury (II) iodide solution is [tex]3.05\times 10^{-8}mol/L[/tex]
A chemist mixes 71.1 g of carbon tetrachloride with 65.4 g of isopropenylbenzene and 4.02 g of 2-ethyltoluene. Calculate the percent by mass of each component of this solution. Be sure each of your answer entries has the correct number of significant digits mass percentー1 □ component 0% carbon tetrachloride isopropenylbenzene 2-ethyltoluene
Answer:
∴ wt% CCl4 = 50.597 %
∴ wt% C9H10 = 46.541 %
∴ wt% C9H12 = 2.861 %
Explanation:
wt% = ((mass solute)/(mass solution))×100⇒ mass sln = 71.1 g CCl4 + 65.4 C9H10 + 4.02 g C9H12
⇒ mass sln = 140.52 g
∴ CCl4:
⇒ wt% CCl4 = ((71.1 g CCl4)/(140.82 g sln))×100
⇒ wt% CCl4 = 50.597 %
∴ C9H10:
⇒ wt% C9H10 = ((65.4 g C9H10)/(140.52 g sln))×100
⇒ wt% C9H10 = 46.541 %
∴ C9H12:
⇒ wt% C9H12 = ((4.02 g C9H12)/(140.52 g sln))×100
⇒ wt% C9H12 = 2.861 %
The percent by mass of each component in the solution is calculated by dividing each component's mass by the total mass and multiplying by 100. The results are 50.62% for carbon tetrachloride, 46.53% for isopropenylbenzene, and 2.86% for 2-ethyltoluene.
Explanation:In order to calculate the percent by mass of each component of the solution, the total mass of the solution needs to be determined first. The total mass would be obtained by summing the individual masses of the carbon tetrachloride, isopropenylbenzene, and 2-ethyltoluene. That is, 71.1 g + 65.4 g + 4.02 g = 140.52 g.
Then, the mass of each component is divided by the total mass and multiplied by 100 to obtain the percentage.
For carbon tetrachloride, the calculation would be (71.1 / 140.52) x 100 = 50.62%. For isopropenylbenzene, the calculation would be (65.4 / 140.52) x 100 = 46.53%. For 2-ethyltoluene, the calculation would be (4.02 / 140.52) x 100 = 2.86%.
Our three significant figures in each of the percentages are due to the fact that our least precise measurement, 4.02 g of 2-ethyltoluene, has four significant figures.
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Consider the steps in coal gasification: C(coal) + H2O(g) → CO(g) + H2(g) ΔH°rxn = 129.7 kJ CO(g) + H2O(g) → CO2(g) + H2(g) ΔH°rxn = -41 kJ CO(g) + 3H2(g) → CH4(g) + H2O(g) ΔH°rxn = -206 kJ Calculate the heat of reaction, ΔH°rxn, for overall reaction for the production of methane, CH4.
The heat of reaction, ΔH°rxn, for overall reaction in coal gasification for the production of methane, CH₄ is 12.4 kJ
From the question,
We are to determine the heat of reaction for overall reaction for the production of methane in coal gasification
The equation for the reaction of coal gasification is
2C(coal) + 2H₂O → CO₂ + CH₄
From the question,
We have the following equations of reactions
(1) C(coal) + H₂O(g) → CO(g) + H₂(g) ΔH°rxn = 129.7 kJ
(2) CO(g) + H₂O(g) → CO₂(g) + H₂(g) ΔH°rxn = -41 kJ
(3) CO(g) + 3H₂(g) → CH₄(g) + H₂O(g) ΔH°rxn = -206 kJ
Multiply (1) by 2 to get
(4) 2C(coal) + 2H₂O(g) → 2CO(g) + 2H₂(g) ΔH°rxn = 259.4 kJ
Now, adding equations (2), (3), and (4), we get
(2) CO(g) + H₂O(g) → CO₂(g) + H₂(g) ΔH°rxn = -41 kJ
(3) CO(g) + 3H₂(g) → CH₄(g) + H₂O(g) ΔH°rxn = -206 kJ
(4) 2C(coal) + 2H₂O(g) → 2CO(g) + 2H₂(g) ΔH°rxn = 259.4 kJ
--------------------------------------------------------------------------------------------------
2C(coal) + 2H₂O(g) → CH₄(g) + CO₂(g) ΔH°rxn = 12.4 kJ
Hence, the heat of reaction, ΔH°rxn, for overall reaction in coal gasification for the production of methane, CH₄ is 12.4 kJ
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The heat of reaction, or ΔH°rxn, for the overall methane production reaction sequence is calculated by summing the enthalpy changes of the individual steps. This value comes out as -117.3 kJ per the application of Hess's Law.
Explanation:In order to calculate the heat of reaction, ΔH°rxn, for overall methane production, we have to use Hess's Law. According to Hess's Law, if a process can be written as the sum of several stepwise processes, the enthalpy change of the total process equals the sum of the enthalpy changes of the various steps. The first reaction has an enthalpy change of 129.7 kJ, the second -41 kJ, and the third -206 kJ.
Now, to find the overall reaction, we will sum up the enthalpy of all these three reactions. So, ΔH°rxn for the overall reaction would be calculated as 129.7 kJ - 41 kJ - 206 kJ = -117.3 kJ. Hence, the heat of reaction for the given set of reactions for the production of methane will be -117.3 kJ.
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A binary compound created by reaction of chromium and an unknown element E contains 68.47% Cr and 31.53% E by mass. If the formula of the compound is Cr2E3, calculate the atomic mass of E.
Answer: The atomic mass of E is 16
Explanation:Please see attachment for explanation
Answer:
The molar mass of E = 15.96 g/mol
Explanation:
Step 1: Data given
The compound Cr2E3 contains 68.47 % Cr and 31.53 % E
The molar mass of Cr = 52 g/mol
⇒ 2*52 = 104 g/mol
The molar mass of Cr2E3 = 2*52 g/mol + 3X
Step 2: Calculate mass of Cr2E3
Cr is 68.47 %
Mass of Cr = 104 grams
Cr2E3 is 100%
Mass of Cr2E3 = 151.89 grams
Molar mass of Cr2E3 = 151.89 g/mol
Step 3: Calculate mass of E
Mass of E3 = mass of Cr2E3 - mass of Cr
Mass of E3 = 151.89 grams - 104 grams
Mass of E3= 47.89 grams
Mass of E = 15.96 grams
The molar mass of E = 15.96 g/mol
Draw the conjugate bases of pyrrole and cyclopentadiene. For pyrrole, please include the N lone pairs. Conjugate Base of Pyrrole: edit structure ... Conjugate Base of Cyclopentadiene
Answer:
Hi
A conjugate acid is a chemical compound formed by the reception of a proton by a base; therefore, it is a base with an added hydrogen ion. On the other hand, a conjugate base is what remains after an acid has donated its proton during a chemical reaction, so it can be said that a conjugate base is a species modified by extracting a proton from an acid.
In pyrrole, the electron pair can be relocated to the ring and its availability is very small. In addition, the concept of aromaticity comes into play.
In the attached file are the schemas of the conjugate bases.
Explanation:
In the hydrogenation of ethylene using a nickel catalyst, the initial concentration of ethylene is 1.50 mol * L−1 and its rate constant (k) is 0.0016 mol * L−1 * s−1.
a. Determine the rate of reaction if it follows a zero-order reaction mechanism.
Answer:
0.0016 mol/(L.s)
Explanation:
The rate of a reaction (r) can be calculated by the initial concentration of the reagent, by the expression:
-r = k*[reagent]ⁿ
Where the minus sign represents that the reagent is disappearing, k is the rate constant, which depends on the temperature, and n is the order of the reaction. For the reaction with more than 1 reagent, each reagent will have its order, which is determined by experiments. So, for n = 0:
-r = 0.0016*(1.50)⁰
-r = 0.0016 mol/(L.s)
Final answer:
The rate of a zero-order reaction is equal to the rate constant, which in the case of the hydrogenation of ethylene using a nickel catalyst is 0.0016 mol L.
Explanation:
To determine the rate of reaction for a zero-order reaction, we use the rate law which states that the rate is independent of the concentration of the reactants. Therefore, for a zero-order reaction, the rate of reaction ( ) is equal to the rate constant (k). Given that the rate constant k is 0.0016 mol L for the hydrogenation of ethylene, the rate of the reaction would simply be the same as the rate constant, which is 0.0016 mol L
A nucleotide is composed of a(n) _____.
a. phosphate group,
b. a nitrogen-containing base, and
c. a hydrocarbon glycerol,
Answer : A nucleotide is composed of a phosphate group and a nitrogen-containing base.
Explanation :
Nucleotide : It is a building block of nucleic acids or we can say that it is building block of DNA and RNA.
It is composed of three sub-unit molecules which are a nitrogenous base, a five-carbon sugar and one phosphate group.
Nucleotide forms covalent bonds with other nucleotide for the formation of the nucleic acid strand.
Hence, a nucleotide is composed of a phosphate group and a nitrogen-containing base.
A nucleotide is composed of a a. phosphate group, a nitrogen-containing base, and a hydrocarbon glycerol.
Explanation:A nucleotide is a fundamental building block of nucleic acids, such as DNA and RNA. It consists of three essential components: a phosphate group, a nitrogen-containing base, and a sugar molecule, not a hydrocarbon glycerol. The phosphate group provides a negatively charged backbone, linking individual nucleotides together through phosphodiester bonds, forming the nucleic acid's backbone.
The nitrogen-containing base can be adenine (A), thymine (T), cytosine (C), guanine (G) in DNA, or uracil (U) instead of thymine in RNA. The sugar molecule, deoxyribose in DNA and ribose in RNA, forms the structural framework to which the phosphate group and nitrogenous base are attached.
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Suppose that the root-mean-square velocity vrms of water molecules (molecular mass is equal to 18.0 g/mol) in a flame is found to be 1150 m/s. What temperature does this represent
The temperature represented by a root-mean-square velocity of 1150 m/s for water molecules in a flame is approximately [tex]5.74 \cdot 10^2^4 Kelvin.[/tex]
The temperature represented by a root-mean-square velocity of water molecules can be calculated using the formula:
[tex]\[ v_{rms} = \sqrt{\frac{3kT}{m}} \][/tex]
Where:
- [tex]\( v_{rms} \)[/tex] = root-mean-square velocity of the molecules (1150 m/s in this case)
[tex]\( k \) = Boltzmann constant (1.38 x 10^-23 J/K)\\\( T \) = temperature in Kelvin (what we're trying to find)\\\( m \) = molecular mass of the water (18.0 g/mol or 0.018 kg/mol)[/tex]
Now, we can rearrange the formula to solve for \( T \):
[tex]\[ T = \frac{m v_{rms}^2}{3k} \][/tex]
Substitute the given values:
[tex]\[ T = \frac{0.018 kg/mol \times (1150 m/s)^2}{3 \times 1.38 \times 10^{-23} J/K} \][/tex]
Calculating:
[tex]\[ T = \frac{0.018 \times 1322500}{4.14 \times 10^{-23}} \]\[ T \approx \frac{23745}{4.14 \times 10^{-23}} \]\[ T \approx 5.74 \times 10^{24} K \][/tex]
The temperature represented by a root-mean-square velocity of 1150 m/s for water molecules in a flame is approximately [tex]5.74 \cdot 10^2^4 Kelvin.[/tex]
To calculate the temperature, we used the formula for root-mean-square velocity and rearranged it to solve for temperature. Plugging in the given values, we obtained the temperature in Kelvin. This extremely high temperature result suggests that either the calculation or the assumptions about the system may not be accurate or applicable in a real-world scenario.
Complete Question:
Suppose that the root-mean-square velocity vrms of water molecules (molecular mass is equal to 18.0 g/mol) in a flame is found to be 1150 m/s. What temperature does this represent?
Write the formula unit equation for this reaction occurring in water: Potassium sulfate and barium chloride are mixed to form potassium chloride and barium sulfate.
1. K2SO4 (s) + BaCl2 (s) → 2 KCl (aq) + BaSO4 (s)
2. K2SO4 (aq) + BaCl2 (aq) → 2 KCl (aq) + BaSO4 (s)
3. 2 K3SO4 (aq) + 3 BaCl2 (aq) → 6 KCl (aq) + 2 Ba3(SO4)2 (s)
The correct formula unit equation for the reaction of potassium sulfate and barium chloride forming potassium chloride and barium sulfate in water is: K2SO4 (aq) + BaCl2 (aq) → 2 KCl (aq) + BaSO4 (s). This is because both potassium sulfate and barium chloride are soluble in water, but barium sulfate is not.
Explanation:The correct formula unit equation for the reaction of potassium sulfate and barium chloride forming potassium chloride and barium sulfate in water is: K2SO4 (aq) + BaCl2 (aq) → 2 KCl (aq) + BaSO4 (s).
This can be justified as when potassium sulfate (K2SO4) and barium chloride (BaCl2) are dissolved in water they dissociate into their respective ions, making them aqueous. The formation of potassium chloride (KCl) acknowledges that potassium ions and chloride ions can be attracted to each other in the water solution, so this is also aqueous. However, barium sulfate (BaSO4) is known to be insoluble in water, and hence, precipitates as a solid (s). Hence, option 2 is correct.
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All of the elements below can exist as network solids EXCEPT 1. As 2. B 3. Si 4. O 5. C
Answer:
4. Oxygen
Explanation:
If heat is added to ice and liquid water in a closed container and after the addition of the heat, ice and liquid water remain, _____
Complete Question:
If heat is added to ice and liquid water in a closed container and after the addition of the heat, ice and liquid water remain, (A) the vapor pressure of the water will decrease. (B) the temperature will increase somewhat. (C) the temperature will decrease somewhat. (D) the vapor pressure of the water will remain constant.
Answer:
A
Explanation:
When heat is added to a system, the internal energy of the molecules increases, and they become more agitated, because of that the temperature intends to increase. But when exists a liquid-vapor equilibrium this increase of temperature may be balanced by the vapor pressure.
The vapor pressure is the pressure that the vapor does when it is in equilibrium with the liquid. So, as higher is it, as easy it will be to the liquid to evaporate. When the temperature increases more liquid will evaporate, because the molecules are more agitated, and so the vapor pressure must increase.
But, if the ice and liquid remain, it indicates that no liquid was evaporated, so, the pressure decreased, to avoid the effect of the temperature, which will remain constant.
Calculate the extinction coefficient where the concentration is in mg/ml and the path length is 1 cm. What dilutions of the stock are each of the prepared solutions (i.e., 1/x)?
The molecular weight of A is 290 g/mole.
Re-calculate the extinction coefficient with the concentration in mM. Note that the newly calculated extinction coefficient will contain an mM-1 term.
Complete Question
The complete question is show on the first uploaded image
Answer:
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Explanation:
This is shown on the second,third , fourth and fifth image
A noble gas atom in the liquid phase is on average surrounded by 10 other atoms. Each pair of atoms contribute g
Answer: noble gases are in reactive.
Explanation: noble gases are present in the right most corner of the periodic table in the 8th group. So their outermost shells are complete. Their boiling point, mass increases down the group. the have strong forces of interaction. their ionization energy decreases down the group
Alkanes with a branch coming off the straight chain are identified as substituted alkanes. What would be the name of a straight chain made of 8 carbons with -CH3 groups on the second and fifth carbons? View Available Hint(s) Alkanes with a branch coming off the straight chain are identified as substituted alkanes. What would be the name of a straight chain made of 8 carbons with -CH3 groups on the second and fifth carbons? 2-methyl-5-methyloctane 2,5-dimethyldecane 2,5-dimethaneoctane 2,5-dimethyloctane
Answer: 2,5-dimethyl octane.
Explanation:
The basic rules for naming of organic compounds are :
1. First select the longest possible carbon chain.
2. The longest possible carbon chain should include the carbons of double or triple bonds.
3. The naming of alkane is done by adding the suffix -ane, alkene by adding the suffix -ene, alkyne by adding the suffix -yne and carboxylic acid by adding the suffix -oic acid.
4. The numbering is done in such a way that first carbon of double or triple bond gets the lowest number.
5. The carbon atoms of the double or triple bond get the preference over the other substituents present in the parent chain.
6. If two or more similar alkyl groups are present in a compound, the words di-, tri-, tetra- and so on are used to specify the number of times of the alkyl groups in the chain.
Thus the name for straight chain made of 8 carbons with [tex]-CH_3[/tex] groups on the second and fifth carbons will be 2,5-dimethyl octane.
An aqueous potassium iodate ( KIO 3 ) solution is made by dissolving 587 grams of KIO 3 in sufficient water so that the final volume of the solution is 5.00 L. Calculate the molarity of the KIO 3 solution.
Answer:
[KIO₃] = 0.548 M
Explanation:
Molarity is a sort of concentration which involves moles of solute in 1L of solution.
Volume of solution 5L
Mass of solution: 587 g
Let's convert the mass to moles (mass / molar mass)
587 g / 214 g/mol = 2.74 moles
Molarity is mol/L → 2.74 mol / 5L = 0.548 M
A chemist adds of a M copper(II) fluoride solution to a reaction flask. Calculate the mass in micrograms of copper(II) fluoride the chemist has added to the flask. Round your answer to significant digits.
The question is incomplete, here is the complete question.
A chemist adds 345.0 mL of a 0.0013 mM (MIllimolar) copper(II) fluoride [tex]CuF_2[/tex] solution to a reaction flask.
Calculate the mass in micrograms of copper(II) fluoride the chemist has added to the flask. Be sure your answer has the correct number of significant digits.
Answer : The mass of copper(II) fluoride is, 0.13 mg
Explanation : Given,
Millimolarity of copper (II) fluoride = 0.0013 mM
This means that 0.0013 millimoles of copper (II) fluoride is present in 1 L of solution
Converting millimoles into moles, we use the conversion factor:
1 moles = 1000 millimoles
So, [tex]0.0013mmol\times \frac{1mol}{1000mmol}=1.3\times 10^{-6}mol[/tex]
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
We are given:
Moles of copper (II) fluoride solution = [tex]1.3\times 10^{-6}mol[/tex]
Molar mass of copper (II) fluoride = 101.5 g/mol
Putting values in above equation, we get:
[tex]1.3\times 10^{-6}mol=\frac{\text{Mass of copper (II) fluoride}}{101.5g/mol}\\\\\text{Mass of copper (II) fluoride}=(1.3\times 10^{-6}mol\times 101.5g/mol)=1.32\times 10^{-4}g[/tex]
Converting this into milligrams, we use the conversion factor:
1 g = 1000 mg
So,
[tex]\Rightarrow 1.32\times 10^{-4}g\times (\frac{1000mg}{1g})=0.13mg[/tex]
Therefore, the mass of copper(II) fluoride is, 0.13 mg
Answer:
the mass of copper(II) fluoride added to the flask is approximately 476,250 micrograms.
Explanation:
To calculate the mass of copper(II) fluoride (CuF2) added to the reaction flask, you need to multiply the volume (in liters) of the solution by its molarity and then convert the result to micrograms.
Given:
Volume of the solution (V) = 0.015 L
Molarity of the solution (M) = 0.500 M
First, calculate the number of moles of copper(II) fluoride using the formula:
Moles (n) = Molarity (M) × Volume (V)
n = 0.500 M × 0.015 L = 0.0075 moles
Now, you need to convert moles to micrograms. One mole of any substance contains Avogadro's number of molecules (6.022 × 10^23). You also need to consider the molar mass of copper(II) fluoride (CuF2), which is the sum of the atomic masses of copper (Cu) and two fluorine (F) atoms:
Molar mass of CuF2 = (1 * Cu) + (2 * F) = 63.5 g/mol (approximately)
Now, calculate the mass in grams:
Mass (g) = Moles (n) × Molar mass (Molar mass of CuF2)
Mass (g) = 0.0075 moles × 63.5 g/mol ≈ 0.47625 g
Now, convert grams to micrograms. There are 1,000,000 micrograms in a gram:
Mass (micrograms) = Mass (g) × 1,000,000
Mass (micrograms) = 0.47625 g × 1,000,000 µg/g = 476,250 µg
So, the mass of copper(II) fluoride added to the flask is approximately 476,250 micrograms.
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Using the Bohr model, determine the energy, in joules, necessary to ionize a ground-state hydrogen atom. Show your calculations.
Answer:
The energy required to ionize the ground-state hydrogen atom is 2.18 x 10^-18 J or 13.6 eV.
Explanation:
To find the energy required to ionize ground-state hydrogen atom first we calculate the wavelength of photon required for this operation.
It is given by Bohr's Theory as:
1/λ = Rh (1/n1² - 1/n2²)
where,
λ = wavelength of photon
n1 = initial state = 1 (ground-state of hydrogen)
n2 = final state = ∞ (since, electron goes far away from atom after ionization)
Rh = Rhydberg's Constant = 1.097 x 10^7 /m
Therefore,
1/λ = (1.097 x 10^7 /m)(1/1² - 1/∞²)
λ = 9.115 x 10^-8 m = 91.15 nm
Now, for energy (E) we know that:
E = hc/λ
where,
h = Plank's Constant = 6.625 x 10^-34 J.s
c = speed of light = 3 x 10^8 m/s
Therefore,
E = (6.625 x 10^-34 J.s)(3 x 10^8 m/s)/(9.115 x 10^-8 m)
E = 2.18 x 10^-18 J
E = (2.18 x 10^-18 J)(1 eV/1.6 x 10^-19 J)
E = 13.6 eV
Imagine you created a toxin such that when a neuron fired an action potential, the toxin would bind immediately to the sodium-potassium pump at the top of the action potential, but the sodium and potassium channels would still function. What process(es) would be affected
Answer:Maintaining resting potential and returning to resting potential after the hyperpolarization phase of an action potential
Explanation:TOXINS are chemical substances which are known to be POISONOUS produced with living organisms that causes harm to other organisms, examples include Venom from snakes which when a person is bitten by a Snake it will possibly lead to death if not adequate treated.
HYPERPOLARIZATION is a term that explains the change in membrane potential due to toxin,it make the membrane more electronegative. When the toxin has hyped the level of Sodium-Potassium level returning to a rest state will be most affected.
In the arrangement of particles within any atom, the outermost sort of particle is always the:________
Answer:
In the arrangement of particles within any atom, the outermost sort of particle is always the electron.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other.
The electron is subatomic particle that revolve around outside the nucleus and has negligible mass. It has a negative charge.
Symbol= e-
Mass= 9.10938356×10-31 Kg
It was discovered by j. j. Thomson in 1897 during the study of cathode ray properties.
While neutron and proton are present inside the nucleus. Proton has positive charge while neutron is electrically neutral. Proton is discovered by Rutherford while neutron is discovered by James Chadwick in 1932.
Symbol of proton= P+
Symbol of neutron= n0
Mass of proton=1.672623×10-27 Kg
Mass of neutron=1.674929×10-27 Kg
In any atom, the outermost type of particle is the electron, specifically the valence electrons in the outermost shell. These electrons play a significant role in chemical reactions and bonding properties of the element. The organization of the Periodic Table reflects patterns in valence electron configurations that correspond to chemical behaviors.
Explanation:In the arrangement of particles within any atom, the outermost sort of particle is always the electron. Electrons are the smallest of the three types of sub-atomic particles, carrying a negative charge and occupying the space outside the atomic nucleus. Inside the nucleus, much larger particles—protons and neutrons—are found, with protons having a positive charge and neutrons being electrically neutral.
The outermost electrons are of particular importance because they are the valence electrons. These are the electrons that reside in the outermost shell, or valence shell, of an atom in its uncombined state, and they play critical roles in determining the chemical properties of an element as well as its ability to form bonds with other atoms. The electron configuration of an atom is notably important because atoms with the same outer electron configurations tend to show similar chemical behavior, as demonstrated in the organization of the Periodic Table.
The number of valence electrons in the outermost shell can define an element's chemical reactivity and the types of bonds it can form. The arrangement of electrons in atoms means that the electrons with the highest energy levels, which are the valence electrons, are more likely to interact in chemical reactions than the core electrons which are closer to the nucleus and have lower energy levels.
On a 12 day wilderness expedition you'll need to heat 5.0kg of water to the boiling point each day. The air temperature will average 25°C. You have available canisters of compressed propane C3H8 fuel, which you'll burn to heat the water. Each canister has 25.g of propane in it. What is the minimum number of fuel canisters you must bring? The standard heat of formation of propane at 25°C is −103.85/kJmol.
To find the minimum number of fuel canisters needed to heat the water to boiling point, calculate the heat required to heat the water and compare it to the heat released from burning one canister of propane.
Explanation:To find the minimum number of fuel canisters needed to heat the water to boiling point each day, we can calculate the heat required to heat 5.0kg of water from 25°C to its boiling point and compare it to the heat released from burning one canister of propane.
The heat required to heat the water is given by the equation Q = mCΔT, where m is the mass of the water, C is the specific heat capacity of water, and ΔT is the temperature change. The specific heat capacity of water is approximately 4.184 J/g°C.
We can use the equation Q = nΔH, where n is the number of moles of fuel burned and ΔH is the heat of combustion, to calculate the heat released from burning one canister of propane. The heat of combustion of propane is given as -2219.2 kJ/mol.
By equating the two equations and solving for n, we can find the number of moles of fuel burned by one canister of propane. Then, we can use the molar mass of propane (44.1 g/mol) to find the mass of propane burned by one canister. Finally, by dividing the total mass of water to be heated by the mass of propane burned by one canister, we can find the minimum number of fuel canisters needed.
By following these calculations, the minimum number of fuel canisters required to heat the water to boiling point each day will be: {number of canisters}.
Calculate the pH of a polyprotic acid given and sketch the titration curves for the following reaction:
A 20.0-mL aliquot of 0.100M of a tartaric acid with 0.100M NaOH
pKa1 = 2.3 pKa2= 4.3
Please calculate the pH when:
1- initial, 0mL of NaOH added
2-pH at first 1/2 equivalence point
3-pH at first equivalence point
4-pH at second 1/2 equivalenec point
5-pH at second equivalence point
6-pH afteter the second equivalence point
Answer: (1). pH = 1.70
(2). pH = 2.3
(3). pH = 3.3
(4). pH = 4.3
(5). pH = 8.41
(6). pH = 10.22
Explanation:
we assume that the formula representation of acid is H₂A
the titration curve has reasonably sharp breaks at both equivalence points, corresponding to the reactions;
H₂A + OH⁻ → HA⁻ + H₂O
HA⁻ + OH⁻ → A²⁻ + H₂O
the volume of NaOH (V₀) at the first equivalent point is,
V₀ = (20.0 mL)(0.100M) / 0.100M = 20.0mL
where volume of NaOH at 1/2 equivalent point is,
V₀/2 = 10.0mL
also Volume of NaOH at the second equivalence (2V₀) point is 40.0mL
the volume of NaOH at 1/2 second equivalent point is,
V₀ + V₀/2 = 30.0mL
Volume of NaOH after second equivalence exceeds 40mL
therefore, at 0 mL NaOH addition;
where the extent of ionization is assumed to be x, we have
H₂A ⇆ HA⁻ + H⁺
where initial: 0.1 M - -
change: -x +x +x
Equili: 0.1-x x x
Kаl = [HA⁻][H⁺] / [H₂A]
10⁻²³ = (x)(x) / (0.1-x)
x = 0.020
[H⁺] = 0.020 M
pH = -log [H⁺]
pH = -log(0.020)
pH = 1.70
(2). at 10 mL NaOH addition
[H₂A]ini = 0.10 M * 20.0 mL = 2 mmol
[OH⁻] = 0.1 M * 10 mL = 1 mmol
after reaction:
[H₂A] = 1 mmol
[H⁻] = 1 mmol
pH = pKa₁ + log [HA⁻] / [[HA⁻]
pH = 2.3 + log 1mmol / 1mmol
pH = 2.3
(3). pH at the first equivalence point is,
pH = 1/2 (pKa₁ + pKa₂)
pH = 1/2(2.3 + 4.3) = 3.3
pH = 3.3
(4). pH at the second 1/2 equivalence point is
pH = pKa₂ = 4.3
pH = 4.3
(5). pH at the second equivalence point;
all H₂A is converted into A²⁻
[A²⁻] = initial moles of H₂A / total volume = (20.0 mL)(0.10 M) / (20.0 + 40.0) mL = 0.033 M
at equilibrium:
A²⁻ + H²O ⇆ HA⁺ OH⁻
0.033 - x
from the Kb₁ expression,
Kb₁ = [OH⁻][HA⁻] / [A²]
Kw/Ka₂ = x²/(0.0333 - x)
10⁻¹⁴/10⁻⁴³ = x²/(0.0333 - x)
x = 2.57 * 10⁻⁶
[OH⁻] = 2.57 * 10⁻⁶M
pH = -log Kw/[OH⁻] = 8.41
pH = 8.41
(6). pH after second equivalence point;
assuming the volume of NaOH is 40.10 mL
after second equivalence point OH⁻ in excess
[OH⁻] = 0.10 M * 0.10 mL / (20 + 40.10) mL = 1.66 * 10⁻⁴ M
pH = 0=-log Kw/[OH⁻] = 10.22
pH = 10.22