Question 1 (True/False Worth 2 points)
(04.03 LC)

When Pb and AlCl3 react together, lead (Pb) can replace aluminum (Al) in the compound because lead is lower on the activity series.

True
False
Question 2(Multiple Choice Worth 4 points)
(04.03 MC)

Which of the following equations has the correct products and is balanced correctly for a reaction between Na3PO4 and KOH?

Na3PO4 + 3KOH → 3NaOH + K3PO4, because K retains the same charge throughout the reaction
Na3PO4 + KOH → Na3OH + KPO4, because K increases in charge from 1+ to 3+ when it is replaced
Na3PO4 + KOH → 3NaOH + K3PO4, because K retains the same charge throughout the reaction
Na3PO4 + KOH → Na3OH + K3PO4, because K increases in charge from 1+ to 3+ when it is replaced
Question 3(Multiple Choice Worth 4 points)
(04.03 LC)

Which of the following is a single replacement reaction?

Ba(OH)2 + H2SO4 → BaSO4 + 2H2O
2Mg + O2 → 2MgO
H2O+ CO2 → H2CO3
Zn + H2SO4 → ZnSO4 + H2
Question 4(Multiple Choice Worth 4 points)
(04.03 MC)

Sodium metal reacts with water to produce hydrogen gas.

What best describes this reaction?

A single replacement reaction takes place because sodium is less reactive than hydroxide ions.
A double replacement reaction takes place because sodium is less reactive than hydroxide ions.
A double replacement reaction takes place because sodium is more reactive than hydrogen.
A single replacement reaction takes place because sodium is more reactive than hydrogen.
Question 5 (True/False Worth 2 points)
(04.03 LC)

A single replacement reaction is a reaction in which one element replaces a similar element within a compound.

True
False
Question 6(Multiple Choice Worth 4 points)
(04.03 MC)

The table shows the nature of reactants and products formed in a certain type of chemical reaction.


Nature of Reactants and Products
Reactants Products
Metal + Ionic compound Metal + Ionic compound


Which of the following is true about the type of chemical reaction?
It is a single replacement reaction, and the anions in the two ionic compounds are different.
It is a single replacement reaction, and the cations in the two ionic compounds are different.
It is a double replacement reaction, and the anions in the two ionic compounds are different.
It is a double replacement reaction, and the cations in the two ionic compounds are different.

Answers

Answer 1

1) Answer is: False.

Balanced chemical reaction: Pb + AlCl₃ → no reaction.

The reactivity series is a series of metals from highest to lowest reactivity. Metal higher in the reactivity series will displace another.

Aluminium (Al) is higher in activity series than lead (Pb).

That means aluminium (Al) is stronger reducing agent than lead and gives electrons easier.

This series are used to summarize information about the reactions of metals with acids or water, double displacement reactions (more reactive metals displace metals with lower reactivity) and the extraction of metals from their ores.

2) Answer is: Na3PO4 + 3KOH → 3NaOH + K3PO4, because K retains the same charge throughout the reaction.

This chemical reaction is double displacement reaction - cations (K⁺ and Na⁺) and anions (PO₄³⁻⁻ and OH⁻) of the two reactants switch places and form two new compounds.

Na₃PO₄ is sodium phosphate.

KOH is potassium hydroxide.

NaOH is sodium hydroxide.

K₃PO₄ is potassium phosphate.

3) Answer is: Zn + H2SO4 → ZnSO4 + H2.

Single replacement is reaction where neutral element metal or nonmetal become an ion as it replaces another ion in a compound.

In this balanced chemical reaction zinc (Zn) replaces hydrogen (H).

Zinc changes oxidation number from 0 to +2 (this is oxidation) and hydrogen change oxidation number from +1 to 0 (reduction).

4) Answer is: A single replacement reaction takes place because sodium is more reactive than hydrogen.

Balanced chemical reaction:

2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g).

Single replacement is reaction where neutral element metal or nonmetal become an ion as it replaces another ion in a compound.

In this balanced chemical reaction sodium (Na) replaces hydrogen (H).

Sodium changes oxidation number from 0 to +1 (oxidation) and hydrogen change oxidation number from +1 to 0 (reduction).

5) Answer is: True.

For example, balanced chemical reaction:

Ca + 2HCl → H₂ + CaCl₂.

Reduction hald reaction: 2H⁺ + 2e⁻→ H₂.

Oxidation half reaction: Ca⁰ → Ca²⁺ + 2e⁻.

In this balanced chemical reaction calcium (Ca) replaces hydrogen (H).

In this chemical reaction, calcium lost two electrons (oxidation, change oxidation number from 0 to +2) and hydrogen gain that two electrons (reduction, change oxidation number from +1 to 0).

6) Answer is: It is a single replacement reaction, and the cations in the two ionic compounds are different.

For example, balanced chemical reaction:  

Ba + MgSO₄ → BaSO₄(s) + Mg.

In this balanced chemical reaction barium (Ba) replaces magnesium (Mg), because barium is higher at activity series.

Sulfate anion (SO₄²⁻) is the same in two ionic compounds, but cations (Mg²⁺ and Ba²⁺) changes.

Single Displacement is reaction where neutral element metal or nonmetal become an ion as it replaces another ion in a compound.  


Related Questions

How has the discovery and usage of the periodic table benefited society?
Select all that apply.

It has enabled scientists to communicate chemical discoveries and results more easily.
It has increased scientists' ability to determine how cations and anions form covalent bonds.
It has increased scientists' ability to predict and discover new elements.
It has led to increased knowledge and usage of elements in technological innovations.

Answers

Final answer:

The discovery and usage of the periodic table has benefited society by enabling easy communication of chemical discoveries, predicting and discovering new elements, and driving technological innovations.

Explanation:

The discovery and usage of the periodic table has benefited society in several ways:

It has enabled scientists to communicate chemical discoveries and results more easily. The organized structure of the periodic table allows for efficient sharing of information between researchers.It has increased scientists' ability to predict and discover new elements. By identifying the patterns and trends in the periodic table, scientists can make educated guesses about the existence and properties of elements that have not yet been discovered or synthesized.It has led to increased knowledge and usage of elements in technological innovations. The periodic table provides a framework for understanding the behavior of different elements, allowing scientists to develop new materials and technologies.

Do you think that the mole should be considered a base unit in the SI system? Explain why or why not.

Answers

The International System of Units (S.I.) is the modern form of the metric system, and is the most widely used system of measurement.

It comprises a coherent system of units of measurement built

- on seven base units, which are

(the ampere, kelvin, second, metre, kilogram, candela, mole)

- a set of twenty prefixes to the unit names and unit symbols that may be used when specifying multiples and fractions of the units.

The system also specifies names for 22 derived units, such as lumen and watt, for other common physical quantities.

So, the mole not should be .... is a base unit in the SI system

Yes, the mole should be considered as a base unit in the SI unit.

A mole is defined as the physical properties of the real object, the carbon atom. Therefore, it is a base unit.

Mole as a base unit in the SI system

A Mole is a base unit of substances in the international SI unit.

It is defined as a collection of exactly 6.022140761023 elementary entities (particles), which can be atoms, molecules, ions, or electrons.

Thus, the mole is considered as a base unit in the SI system, because it defined as physical properties of real objects.

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Why is a bush or tree a more accurate then a line to describe how hominds developed into modern humans

Answers

The human “family tree” may be better described as a “family bush,” within which it is impossible to connect a full chronological series of species, leading to Homo sapiens, that experts can agree upon.

When so much solute is added that no more will dissolve, what type of solution has been created? NEED HELP ASAP

Answers

The simplest answer and the correct one is saturated. You can try this at home to see what it looks like. Take a  glass and fill it to the 1/2 full mark. Make sure the water is on the coolish side. Start putting measured amounts of salt in the water. Do this until you see salt on the bottom of the glass. The solution is now saturated.

Empty the glass. Put the same amount of water in the glass but make it much  warmer. Put the same amount of salt in the glass. It should not be saturated -- that is there should be no salt on the bottom.

So temperature determines saturation. But more important, you should get an idea of what saturation is.

Why is energy required to remove an electron from an atom?

Answers

Electrons in an atom are held there by the force of attraction exerted by the positive charge of the nucleus on the negative charge of the electron. Energy is required to remove an electron from atom to overcome this attractive force.

Ce procent de impuritati contine un minereu de siderit, daca din 1500kg minereu s-au obtinut 700kg fier 90% ?

Answers

FeCO3  ==> Fe + produsi minoritari.


m Fe impur= 700 kg


puritatea (p) = masa pura (mp)/ masa impura (mi) x 100

mp= p x mi / 100 sau mp = p/100 x mi => mp Fe = 90/100 x 700 = 630 kg Fe pur.


M FeCO3= 115.85 kg/kmol

115.85 kg FeCO3 .... 55.85 kg Fe

     x kg FeCO3  ........630 kg Fe

x= 630 * 115.85 /55.85 = 1306.81 kg FeCO3 (mp in formula puritatii)

p=mp/mi x 100

mi FeCO3 = 1500 kg

mp FeCO3=1306.81 kg

p=1306.81 / 1500 x 100 = 87.12% puritate Siderit




Copper wire is used in electrical wiring because the metallic bonding between the atoms aids with the ___________ of the material.

Answers

Final answer:

Copper wire is used in electrical wiring because its metallic bonding aids with conductivity of the material.

Explanation:

The metallic bonding between the atoms aids with the conductivity of the material.

Copper wire is used in electrical wiring because it has high electrical conductivity. Metallic bonding is responsible for the free flow of electrons in copper, allowing it to conduct electricity efficiently. This property makes copper an ideal material for conducting electric current in various appliances.


Sea turtles are found in the waters of Georgia. Building on the coast has destroyed their nesting sites. How will this MOST LIKELY affect the sea turtles usually found on the Georgia coast?
A) The turtles will begin laying more eggs.
B) The turtles will build nests in other places.
C) The turtles will no longer be found in Georgia.
D) This will not affect the number of turtles in Georgia.

Answers

The correct answer is option C, that is, the turtles will no longer be found in Georgia.  

Due to the presence of protected dunes and temperate climate appropriate for nesting activities, the barrier island beaches of Georgia host an average of 1000 sea turtles nests in a year.  

However, the main danger to sea turtles in Georgia is the damage of their eggs and nests and offshore mortalities related to commercial longline fishing or shrimping activities. With the development going on in the coastal regions where the turtles thrive, a time will come when one will no longer witness any turtle along the coast of Georgia.  


Answer:

C

Explanation:

The turtles will no longer be found in Georgia.

Give the correct thermochemical equations for a (cacl2+h2o) pack and (nh4no3+h2o) pack.

Answers

In a pack of CaCl2 and H2O, hydrolysis of Ca+2 will occur

This will result in formation of Ca(OH)2.

The reaction is exothermic in nature

so the balanced thermo-chemical equation will be

CaCl2(aq) + H2O (l)  ---> Ca(OH)2   + 2HCl + Heat


In a pack of NH4NO3 and H2O hydrolysis of NH4+ will occur as

NH4NO3 (aq)  + H2O(l)  + Heat ---> NH4OH(aq)  + HNO3 (aq)

It is an endothermic reaction


A substance registers a temperature change from 20°c to 40°c. to what incremental temperature change does this correspond?

Answers

if u are multiplaying it would be 80 percent more likely
or if u are subtracting it would be 20 percent

The incremental temperature change is 20°C or 50%.

What is incremental temperature change ?

Incremental temperature change is the change in the temperature of any substance when it is increased from its original temperature. Incremental temperature change is always measured as percentage increase in the rate of temperature.

How to calculate the incremental temperature change ?

Temperature is increased from 20°C to 40°C .

Thus incremental change in temperature,

  ΔT = Final temperature - Initial temperature

∴ ΔT = 40°C  -  20°C  =  20°C

Also percentage change in temperature ,

(ΔT / Final temperature) × 100 %

⇒ (20°C / 40°C) × 100 %

⇒ (1/2) × 100 %

∴ Percentage change = 50%

Thus incremental temperature change is 20°C or 50%

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Complete the paragraph to describe the characteristics of silicon tetrachloride molecule (SiH4). the Lewis structure and the table of electronegativities are given.

The bond polarities of SiH4 are _____, the molecular shape is _____, and the molecule is _____.

Blank Options 1: Polar, Nonpolar
Blank Options 2: trigonal pyramidal, trigonal planar, tetrahedral, linear, bent
Blank Options 3: Polar, Nonpolar

Answers

Final answer:

Silicon tetrachloride (SiH4) is a covalent tetrahedral molecule with a trigonal pyramidal shape. It is nonpolar and has a low boiling point of 57 °C.

Explanation:

Silicon tetrachloride (SiH4) is a covalent tetrahedral molecule with a trigonal pyramidal shape. The Lewis structure for SiH4 would show the silicon atom in the center with four chlorine atoms bonded to it. Each chlorine atom would have a lone pair of electrons, causing the molecule to have a trigonal pyramidal shape.

The electronegativity values of silicon and chlorine are 1.9 and 3.2 respectively, indicating a polar covalent bond between silicon and chlorine. However, due to the symmetry of the molecule, the dipole moments cancel each other out, resulting in a nonpolar molecule. Silicon tetrachloride is a colorless liquid with a low boiling point of 57 °C.

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Final answer:

Silicon tetrahydride (SiH4) is a nonpolar molecule with a tetrahedral shape due to the central silicon atom being sp³ hybridized. Even though Si-H bonds are polar, the symmetry of the molecule results in a nonpolar overall molecule.

Explanation:

The bond polarities of SiH4 are Nonpolar. SiH4, or Silicon tetrahydride, is a covalent molecule with tetrahedral structure, in which Silicon (Si) forms four single bonds with four Hydrogen (H) atoms. Central Silicon atom is sp³ hybridized, which results in a Tetrahedral molecular shape. Even though the Si-H bonds are polar because of the difference in electronegativities of Si and H, the bond dipoles cancel each other because of the molecule's symmetry, making the whole molecule Nonpolar.

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Suppose the volume of a container is decreased, but the same number of gas molecules is present at the same temperature. What will happen to the molecules?

The molecules will increase in number.

The molecules will decrease in number.

There will be more molecules per unit volume.

There will be less molecules per unit volume.

Answers

Answer: Option (C) is the correct answer.

Explanation:

When the volume of a container is decreased and same number of gas molecules are present inside the container at the same temperature then it means that more number of gas molecules are spread per unit volume.

As earlier when the volume of container was more then the molecules were widely spread inside the container but on decreasing the volume of container, molecules come closer to each other and hence there will be increase in molecules per unit volume.  


Answer:

It is C

Explanation:

Triethylenemelamine is used in the plastics industry and as an anticancer drug. Its analysis is 52.93% carbon, 5.92 % hydrogen, 41.15% nitrogen. The molecular mass of triethylenemelamine is 204.2 g/mol. What is its empirical formula? What is its molecular formula?

Answers

Assuming total mass to be 100 g

Mass of C = 52.93 g

=> Moles of C = [tex]52.93 g *\frac{1 mol}{12gC} =4.41 mol C[/tex]

Mass of H = 5.92 g

=> Moles of H=[tex]5.92g*\frac{1mol}{1.01g}=5.86molH[/tex]

Mass of N = 41.15 g

=>Moles of N=[tex]41.15g*\frac{1 mol}{14 g}=2.94mol N[/tex]

Simplest mole ratio of the atoms in the compound:

[tex]C_{\frac{4.41mol}{2.94mol} } H_{\frac{5.86mol}{2.94mol} }N_{\frac{2.94mol}{2.94mol} } =C_{1.5}H_{2}N_{1} or(C_{1.5}H_{2}N_{1})_{2}=>C_{3}H_{4}N_{2}[/tex]

Empirical formula mass=[tex](3*12)+(4*1.01)+(2*14)=68.04g[/tex]

Multiple n = [tex]\frac{204.2}{68.04}=3[/tex]

Molecular formula= [tex](Empirical formula)_{n} =(C_{3}H_{4}N_{2})_{3}=C_{9}H_{12}N_{6}[/tex]


Final answer:

The empirical formula of triethylenemelamine is determined to be C₃H₄N₂ based on the given percentage composition. By comparing the molecular mass of triethylenemelamine to the mass of the empirical formula unit, the molecular formula is found to be C₆H₈N₄.

Explanation:

To determine the empirical formula and molecular formula of triethylenemelamine based on its percent composition (52.93% carbon, 5.92% hydrogen, 41.15% nitrogen) and molecular mass (204.2 g/mol), follow these steps:

Calculate the moles of each element based on 100 g of the compound.
For Carbon: (52.93 g / 12.01 g/mol) = 4.41 moles
For Hydrogen: (5.92 g / 1.008 g/mol) = 5.87 moles
For Nitrogen: (41.15 g / 14.01 g/mol) = 2.94 moles

Determine the simplest whole number ratio of the elements by dividing by the smallest number of moles, which in this case is 2.94 moles (N). This gives:
C: 4.41 / 2.94 ≈ 1.5
H: 5.87 / 2.94 ≈ 2
N: 2.94 / 2.94 = 1

Since the ratio needs to be in whole numbers, multiply each by 2 to get C₃H₄N₂ as the empirical formula.

To find the molecular formula, divide the molecular mass of triethylenemelamine (204.2 g/mol) by the mass of the empirical formula unit (C₃H₄N₂ = 3(12.01) + 4(1.008) + 2(14.01) ≈ 84.1 g/mol), getting approximately 2.43. Since molecular formulas must be whole numbers, this indicates the empirical formula must be multiplied by 2, giving C₆H₈N₄ as the molecular formula of triethylenemelamine.

PLEASE HELP ASAP!!THANKS!

Balance the following and label what type of reaction is taking place: 
C5H9O + O2? CO2 + H2O

Answers

The given reaction is C₅H₉O + O₂ → CO₂ + H₂O

On balancing the equation we get:  

20 C₅H₉O + 90 O₂ → 100 CO₂ + 9 H₂O

This is a single replacement type of reaction. A single replacement reaction, also called a single-displacement reaction, refers to a kind of chemical reaction where an element reacts with a compound and occupies the place of another element in that compound.  


Evaluate why acids are able to conduct electricity. Then describe which types of acids are better conductors and why.

Answers

Acids produce H+ ions in solution.

Since it produces ions in solution and ions can carry current.

Hence acids can conduct electricity as it produces ions in solution.

Strong acids dissociate completly and produce more ions (than weaker acids which do not dissociate completly) so strong acids are better conductors of electricity.


A 0.1326 g sample of magnesium was burned in an oxygen bomb calorimeter. the total heat capacity of the calorimeter plus water was 5,760 j/°c. if the temperature rise of the calorimeter with water was 0.570°c, calculate the enthalpy of combustion of magnesium. mg(s) + 1/2o2(g) →mgo(s)

Answers

 The enthalpy  of  combustion  of magnesium  is -601.3  kj/mol


calculation

  ΔH = cΔT

   C( heat capacity) =5,760 j/°c

    ΔT = 0.570°c

 ΔH = 5760 j/°c  x 0.570 °c = 3283.2 j

convert 3283.2 j into Kj

1 kj = 1000 j

 kj ?  =3283.2 j

 by cross multiplication

={ (3283.2  j  x 1 kj) / 1000 j}  =3.2832 kj

Find the  moles of Mg

moles = mass÷ molar mass  

from periodic table the molar mass   of Mg = 24.3 g/mol

= 0.1326 g÷ 24.3 g/mol =0.00546 moles


find ΔH in KJ/mol

 =  3.2832 kj/ 0.00546 moles = 601.3 Kj/mol


since  heat  is released during combustion the ΔH  is  = - 601.3 kj/mol


 

How do you think bubbles affect sound in the global ocean?

Answers

Final answer:

Bubbles in the ocean alter sound propagation by scattering and absorbing sound, which affects acoustic communication and the operation of sonar. Increased bubbles from thermal pollution can also decrease dissolved oxygen levels, impacting marine life.

Explanation:

The presence of bubbles in the global ocean can significantly affect sound propagation. Bubbles can scatter and absorb sound, altering its speed and direction. Consequently, this can influence acoustic communication and the effectiveness of sonar systems used by marine animals and humans for navigation, communication, and detection. For instance, dolphins rely on echolocation to navigate and hunt in the ocean, and bubbles can disrupt the transmission of these sound waves. Additionally, in areas with a high bubble content due to thermal pollution or natural gas seepage, sound may not travel as predictably, which could have navigational implications for sea life and technological systems.

Another aspect where bubbles can play a role is during thermal pollution events, where the solubility of gases in water decreases as the water temperature increases. This leads to the formation of more bubbles, which can reduce the amount of dissolved oxygen in the water, critically affecting marine life. Moreover, sonar technology, which relies heavily on the transmission of sound for detecting objects underwater, can be affected by the presence of bubbles as they change the medium through which sound waves travel. This can make the sonar less precise or reliable.

A non-native organism that is released into a new ecosystem, such as Kudzu in the southeastern United States is called a
A) pioneer species.
B) threatened species.
C) endangered species.
D) non-indigenous species.

Answers

Answer is: D) non-indigenous species.

Non-indigenous species or an introduced species is a species living outside its native area, but which has arrived there by human activity, either deliberate or accidental.

Kudzu (Japanese arrowroot) was introduced from Japan into the United States at the Japanese pavilion in the 1876 Centennial Exposition in Philadelphia.

The United States Forest Service estimated the rate of spreading of plant Kudzu to be 2500 acres per year.

Answer:

D. non-indigenous species.

Explanation:

Which compound is held together by ionic bonds?

A. S02
B. H20
C. CaCl2
D. CH4

Answers

Answer is: C. CaCl2.

Name of this chemical compounds is calcium chloride.

Calcium chloride is a inorganic salt with ionic bonds between calcium and chlorine.

It is a colorless crystalline solid at room temperature, highly soluble in water.

Calcium form cation with positive charge 2+ and chlorine form anion with negative charge 1-.

Electron configuration of calcium atom: ₂₀Ca 1s² 2s² 2p⁶ 3s² 3p⁶ 4s².  

Atomic number of calcium is 20, it means that it has 20 protons and 20 electrons, so atom of calcium is neutral.  

When calcium lost two electrons, it will have 20 protons (positive charge) and 18 electrons (negative charge), which means it has two protons more and it has +2 oxidation number.

Which electrons in a calcium atom in the ground state have the greatest effect on the chemical properties of calcium

Answers

Answer is: the two electrons in the fourth shell.

Atomic number of calcium is 20, it means that it has 20 protons and 20 electrons, so atom of calcium is neutral.  

Electron configuration of calcium atom: ₂₀Ca 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²; calcium has two valence electrons (4s²).  

In reactions it lose those two electrons ang form cation with positive charge 2+.

Atomic number is the number of protons, which is characteristic of a chemical element.

Beryllium, magnesium,calcium and strontium are alkaline earth metals. The elements have very similar properties.

Alkaline earth metals have in common an outer s- electron shell (two electrons).

Valence electrons have the greatest effect on the chemical properties of calcium

Further explanation

Electrons can move the shell up or down by releasing energy or absorbing energy

Excited electrons show higher electron transfer to the shell by absorbing energy

So it can be concluded that there are 2 conditions:

Ground state is the state of electrons filling skins with the lowest energy levels.

Excited state is the state of electrons which occupies a higher energy level

The state of excited electrons can be seen from the presence of electrons which do not fill the skin completely but fill the skin afterwards

Ca has atomic number 20 so the electron configuration is:

1s² 2s² 2p⁶ 3s² 3p⁶ 4s²

This configuration can be said in Ground state conditions

Elemental properties can be determined by its valence electrons (electrons which fill electrons in the outer shell)

The valence electrons of an element indicate in what group and period the element is located in the periodic system so that its properties can be determined

The period of an element is determined from the valence shell (the biggest main quantum number (n) )

Groups of chemical elements are divided into two, namely:

Group A, occupying sub shell s and p

Group B, occupying sub shell d

If we look at valence electrons from Ca atoms then:

period = 4 group = 2A

So that the Ca Atom is located in the alkaline earth group, together with beryllium (Be), magnesium (Mg), strontium (Sr), barium (Ba), and radium (Ra)

So the  chemical properties of calcium :

- forming bases - reactive - strong reducing agent

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ASAP
Which of the following would have the greatest mass?


15.0 moles of N

5.0 moles of Zn

20.0 moles of H

1.0 moles of Pb

Answers

In order to find the mass (in grams) of an element, you just need to multiply the no. of moles given by the atomic mass of the element, which can be found in a periodic table.

mass of 15.0 moles of N= 15.0 x 14.0 = 210g

mass of 5.0 moles of Zn= 5.0 x 65.4 = 327g

mass of 20.0 moles of H= 20.0 x 1.0 = 20g

mass of 1.0 moles of Pb= 1.0 x 207.2 = 207.2g

Therefore, since 327g is the greatest mass out of the 4 options, the answer is 5.0 moles of Zn.

Which of the following is equal to the number of particles in 36 grams of carbon-12?

B. 3 moles
A. 3:1 molar mass
C. 3:1 mole ratio
D. 1:3 molar volume

Answers

The quick answer is B

3 moles

A mole has an alternate definition of 6.02 * 10^23 particles or atoms (in this case) that make it up.

A is possible, but it is not the question.

C is possible, but it is not the question.

I've never directly seen D before. It is used with gases (indirectly).

The answer is B

3 moles

What is the name for the Fe2+ cation?

Iron ion

Iron (II) ion

Ironide

Ferride ion

Answers

Answer:

Iron (II) ion.

Explanation:

Fe²⁺ is a cation of ion that lost 2 electrons.It can be named as iron (II) ion.Iron is the name of the metal, and (II) means that it is the cation of Fe metal that lost 2 electrons.

While Iron ion may be Fe²⁺ or Fe³⁺.

So, the right choice is:  iron (II) ion.

Answer:

The correct answer is the option: Iron (II) ion.

Explanation:

Hello! Let's solve this!

El Hierro (Fe) has two valence numbers. Fe + 2 and Fe +3.

The +2 and +3 indicate that iron lost two or three electrons respectively.

In this case the ion is Fe + 2, this cation is called the Iron (II) ion

We conclude that the correct answer is the option: Iron (II) ion.

Shannon needs 9 feet of ribbon for an art project. How many inches of ribbon should she buy if she is making 4 projects

Answers

432 inches

Each project is 9 feet, and she is making 4 projects, so multiply 9 by 4 to find the number of feet needed. You should get 36. Each foot is equal to 12 inches, so multiply 36 by 12 to get 432 inches.

Answer: 432 inches

Explanation:

Given : length of ribbon needed by Shannon for an art project = 9 feet

As we know : 1 feet = 12 inches

9 feet =[tex]\frac{12}{1}\times 9=108inches[/tex]

Thus if for 1 project , length of ribbon required is = 108 inches

For 4 projects , length of ribbon required is =[tex]\frac{108}{1}\times 4=432inches[/tex]

Thus 432 inches of ribbon should she buy if she is making 4 projects.

For the reaction Na + H2O → NaOH + H2, what are the reactants, products, and correct coefficients in the balanced equation? Reactants: 1Na and 1H2O; products: 1NaOH and 1H2 Products: 2Na and 1H2O; reactants: 2NaOH and 1H2 Products: 3Na and 2H2O; reactants: 3NaOH and 2H2 Reactants: 2Na and 2H2O; products: 2NaOH and 1H2

Answers

The correct answer is reactants 2Na and 2H₂O and products 2NaOH and 1H₂.  

The given unbalanced chemical equation is:  

Na (s) + H2O (l) → NaOH (aq) + H₂ (g)

From the equation, it can be seen that there are three atoms of hydrogen on the products side, however, only two on the reactant's side. So, in order to balance the equation, one needs to multiply the sodium hydroxide by 2 to get a total of 4 atoms of hydrogen on the product's side.  

This will enable one to readily double the number of molecules of water to get 4 atoms of hydrogen on the reactants side, and then balance the atoms of sodium by multiplying the sodium metal by 2. The balanced equation obtained is:  

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


In the given chemical reaction, Reactants: 2Na and 2H₂O and Products: 2NaOH and 1H₂. Therefore, option D is correct.

In the balanced equation, the coefficients indicates the relative number of moles of each substance involved in the reaction. The balanced equation for the reaction between sodium (Na) and water (H₂O) to produce sodium hydroxide (NaOH) and hydrogen gas (H₂) is: 2Na + 2H₂O → 2NaOH + H₂

This balanced equation shows that 2 moles of sodium reacts with 2 moles of water to produce 2 moles of sodium hydroxide and 1 mole of hydrogen gas.

Learn more about chemical reactions, here:

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how did quantum mechanics change our understanding of atoms?


A. in quantum mechanics, electrons exist in a cloud-shaped area outside the nucleus.


B. in quantum mechanics, photons exist in a cloud-shaped area outside the nucleus.


C. in quantum mechanics, photons are a part of the nucleus along with electrons.


D. in quantum mechanics, photons are a part of the nucleus along with protons.

Answers

A. in quantum mechanics, electrons exist in a cloud-shaped area outside the nucleus.

Answer:

The correct answer is option A.

Explanation:

Schrodinger proposed the mechanic model of atom in which he defined the location of electrons inside an atom by electron cloud in 3-d space. And in order to locate them he introduced the concept of quantum numbers.

Where as photons are the discrete  packet or bundle of energy related to electromagnetic radiations.

The following solutions are prepared by dissolving the requisite amount of solute in water to obtain the desired concentrations. Rank the solutions according to their respective osmotic pressures in decreasing order assuming the complete dissociation of ionic compounds. Rank from highest to lowest osmotic pressure. To rank items as equivalent, overlap them. 1M C6H12O6, 1M MgCl2, 2M CH3OH, 1M NaCl

Answers

Answer:

C₆H₁₂O₆ < NaCl ≈ CH₃OH < MgCl₂

Step-by-step explanation:

The formula for osmotic pressure (Π) is

Π = icRT

If T is constant,

Π = kic

C₆H₁₂O₆:

Π = k × 1 × 1 = k

MgCl₂:

Π = k × 3 × 1 = 3k

CH₃OH:

Π = k × 1 × 2 = 2k

NaCl:

Π = k  × 2 × 1 = 2k

The order of osmotic pressures is  

C₆H₁₂O₆ < NaCl ≈ CH₃OH < MgCl₂

MgCl₂ > NaCl = CH₃OH > C₆H₁₂O₆ or MgCl₂ > CH₃OH = NaCl > C₆H₁₂O₆.

Further explanation

Given:

1 M C₆H₁₂O₆1 M MgCl₂2 M CH₃OH1 M NaCl

Question:

Rank the solutions according to their respective osmotic pressures in decreasing order assuming the complete dissociation of ionic compounds.

The Process:

The osmotic pressure of a nonelectrolyte solution is calculated as follows:

[tex]\boxed{ \ \pi = MRT \ }[/tex]

The osmotic pressure of an electrolyte solution is calculated as follows:

[tex]\boxed{ \ \pi = MRTi \ }[/tex]  

The van't Hoff factor is i = 1 + (n - 1)α, with  

n = number of ions, and  α = degree of dissociation.

In our problem, assuming the complete dissociation of ionic compounds results in α = 100% and i = n.

From the information above, each type of solution can be prepared as follows:

C₆H₁₂O₆ (glucose) and CH₃OH (methanol) are non-electrolyte solutions.MgCl₂ and NaCl are strong electrolyte solutions.[tex]\boxed{ \ MgCl_2 \rightarrow Mg^{2+} + 2Cl^- \ } \rightarrow \boxed{ \ i = n = 3 \ ions \ }[/tex][tex]\boxed{ \ NaCl \rightarrow Na^{+} + Cl^- \ } \rightarrow \boxed{ \ i = n = 2 \ ions \ }[/tex]

Now we compare the amount of osmotic pressure from each solution.

1 M C₆H₁₂O₆ ⇒ [tex]\boxed{ \ \pi = 1 \times RT \ } \rightarrow \boxed{ \ \pi = RT \ }[/tex] in atm.1 M MgCl₂ ⇒ [tex]\boxed{ \ \pi = 1 \times RT \times 3 \ } \rightarrow \boxed{ \ \pi = 3RT \ }[/tex] in atm.2 M CH₃OH ⇒ [tex]\boxed{ \ \pi = 2 \times RT \ } \rightarrow \boxed{ \ \pi = 2RT \ }[/tex] in atm.1 M NaCl ⇒ [tex]\boxed{ \ \pi = 1 \times RT \times 2 \ } \rightarrow \boxed{ \ \pi = 2RT \ }[/tex] in atm.

From the above results, it can be observed that 2 M CH₃OH and 1 M NaCl have the same osmotic pressure.

Thus, the rank of the solutions according to their respective osmotic pressures in decreasing orders is MgCl₂ > NaCl = CH₃OH > C₆H₁₂O₆ or MgCl₂ > CH₃OH = NaCl > C₆H₁₂O₆.

- - - - - - - - - -

Notes:

Colligative properties are physical properties of a solution that depend on the amount of solute expressed as concentration. One of the colligative properties is osmotic pressure (π).Osmosis is a spontaneous process in which a solvent molecule passes through a semipermeable membrane from a dilute solution (lower solute concentration) to a more concentrated solution (higher solute concentration). The pressure that causes the osmosis process to stop is considered osmotic pressure. We can also observe osmotic pressure as the external pressure needed to prevent the osmosis process. The required external pressure is the same as the osmotic pressure of the solution.Learn moreAbout electrolyte and nonelectrolyte solutions https://brainly.com/question/5404753Calculating the pH value of weak base https://brainly.com/question/9040743To make a 0.500 M solution, one could take 0.500 moles of solute and add? https://brainly.com/question/10278982

An electron and a proton attract each other as a result of _____ forces.

a. inertial

b. gravitational

c. compression

d. electromagnetic

Answers

It should be electromagnetic force as it is the force in which particles with opposing charges attracts each other(proton(+) and electron(-))

The correct answer is D. Electromagnetic

Explanation:

Electron and protons are both subatomic particles that differ in their mass and other features including electromagnetic charges. Indeed, protons are positively charged, while electrons are negatively charged. This difference in electromagnetic charges causes electrons to be attracted to electrons, and vice versa due to electromagnetic forces as particles with different charges attract each other while those with the same charges repel each other. Thus, an electron and a proton attract each other as a result of electromagnetic forces.

What is the three-dimensional shape of the molecule with this Lewis structure.

H-Be-H

A. Bent
B. Linear
C. Tetrahedral
D. Trigonal Plannar

Answers

I would have to say B. Linear

I hope this helps!

Cheers, July.


Answer : The correct option is, (B) Linear

Explanation :

Formula used  :

[tex]\text{Number of electrons}=\frac{1}{2}[V+N-C+A][/tex]

where,

V = number of valence electrons present in central atom

N = number of monovalent atoms bonded to central atom

C = charge of cation

A = charge of anion

Now we have to determine the hybridization of the [tex]BeH_2[/tex]  molecules.

[tex]\text{Number of electrons}=\frac{1}{2}\times [2+2]=2[/tex]

The number of electrons is 2 that means the hybridization will be [tex]sp[/tex] and the electronic geometry of the molecule will be linear.

The three-dimensional shape of the molecule with the Lewis structure are shown below.

explain why a suspension is considered a heterogeneous mixture.

Answers

Because you can see more than one substance in the mixture
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