Need help with chemistry homework. All questions are listed below.

Homework Ch13

Q5 A solution is made by dissolving 27.6 g of nickel(II) chloride, NiCl2, in enough water to make exactly 500 mL of solution. Calculate the concentration (molarity) of NiCl2 in mol/L (M).

_______ M NiCl2

Q6 Calculate the mass, in grams, of K2Srequired to prepare exactly 250 mL of a 0.510-M solution of K2S. _____ g

Find one more question in the attachment.

Homework Q ch14

Question 1

Which of these statements about cohesive forces is/are correct?

I.In the absence of cohesive forces, most substances would be solids.II.Cohesive forces result in the formation of liquid droplets or spheres.III.A spherical shape minimizes the surface-area-to-volume ratio.

I only

II only

I and III

II and III

I and II

Question 2

Which of these statements about liquids is/are correct?

I.Increased molecular motion results in increased rate of evaporation.II.Liquids take the shape of their container.III.Liquids have relatively low compressibility compared to gases.

I only

II only

I and II

II and III

I, II, and III

Question 3

Which of the following statements about solids is/are correct?

I.Solids have lower kinetic energy than liquids.II.Molecules present in solids are in fixed positions.

III.The shape of a solid is independent of the container that holds it.

I only

II only

I and II

II and III

I, II, and III

Question 4

The point at which a liquid gets converted to a gas is known as the _____.

boiling point

melting point

sublimation point

deposition point

freezing point

Question 5

Which substance has the greatest dispersion force?

CH4

F2

He

Cl2

O2

Question 6

Which substance is likely to have the highest vapor pressure?

CH3CH2CH2CH3

CH3CH2CH2CH2CH3

CH3CH2CH2CH2CH2CH3

CH3CH2CH2CH2CH2CH2CH3

The vapor pressure is about the same for all the listed molecules.

Question 7

The dominant intermolecular attractive force(s) between CH3Cl molecules is/are _____.

dipole forces

dispersion forces

hydrogen bonding

London forces

volatile forces

Question 8

Which of these substances is polar?

CO2

SO2

Cl2

CH4

BF3

Question 9

Which of these substances is nonpolar?

H2O

SO2

HF

CCl4

CH3F

Question 10

In which of the following does hydrogen bonding occur?

Nonpolar molecules containing hydrogen

All molecules that contain hydrogen

Molecules that contain hydrogen and carbon

Molecules that contain hydrogen bonded to either nitrogen, oxygen, or fluorine

All of these

Question 11

Molarity is defined as the number of moles of _____ per liter of _____.

solvent; solution

solution; solvent

solute; solution

solution; solute

solvent; solute

Question 12

What is the unit of molarity?

Grams per mole

Grams per liter

Moles per liter

Molecules per liter

Molecules per mole

Question 13

What is the concentration in molarity of a solution made by dissolving 20.0 grams of KOH in 150.0 mL of H2O (molar mass of KOH = 56.1056 g/mol)?

0.133 M

0.421 M

2.37 M

4.35 M

7.5 M

Question 14

A 5% acetic acid solution contains _____ grams of acetic acid per _____ grams of solution.

5; 10

95; 100

100; 500

5; 500

50; 1000

Question 15

For solutions in water, a part per million is roughly equivalent to _____.

g/mL

mg/mL

g/L

mg/L

kg/mL

Question 16

Which of these is a benefit of water's unique freezing properties?

Water freezes on the surface of lakes, allowing marine life underneathto survive during winter.

Water freezes at the bottom of the ocean, cooling volcanic eruptions.

Water freezes in the cracks within rocks, preventing erosion of mountains.

Water freezes in the cells of living bodies, protecting them from externalviruses.

Water freezes in living bodies, minimizing their dependence on external sources of water.

Question 17

What fraction of water on the planet is in readily usable forms such as streams and lakes?

98%

47%

2.6%

14%

0.014%

Question 18

Which of these elements is/are the primary component(s) in hard water?

I.MagnesiumII.IronIII.CalciumIV.Sodium

I only

III only

II and III

I and III

II and IV

Question 19

Which of these is a result of dumping human waste near or directly into ground or surface waters?

Hard water

Soft water

Biological contaminants

Radioactive contaminants

Inorganic contaminants

Question 20

Which of these water treatment systems removes organic contaminants?

Carbon filtering

Water softening

Reverse osmosis

Coagulation

Chlorination

Question 21

Water softeners are used to avoid the undesirable effects of hard water. These water softeners are charged with _____ ions.

sodium

calcium

potassium

chlorine

magnesium

Question 22

Which of these statements about boiling point is/are incorrect?

I.Boiling occurs when there is sufficient molecular energy to convert a liquid to a gas.II.The stronger the cohesive forces, the higher the boiling point.

III.Boiling results in the cleavage of chemical bonds.

I only

II only

III only

I and III

II and III

Question 23

Substance A contains stronger cohesive forces than substance B. Which of the following statements is true?

Substance A will have a higher boiling point and higher vapor pressure than substance B.

Substance A will have a lower boiling point and lower vapor pressure than substance B.

Substance A will have a lower boiling point and higher vapor pressure than substance B.

Substance A will have a higher boiling point and lower vapor pressure than substance B.

Substance A will have the same boiling point and vapor pressure as substance B.

Question 24

Which of these substances in its/their liquid form contain(s) hydrogen bonds?

I.HgII.H2OIII.C2H5OHIV.CH3CH3

I only

II, III, and IV

I and II

II and III

I, II, and III

Question 25

Which of these is not a unit for measuring the concentration of solutions?

M

m

ppm

atm

mg/L