AP CH 11 & 13

Use the IMForce

1

What is the predominant attractive force between the particles in MgF₂?

Ionic

2

Hydrogen bonding is a special case of ________. [identify IMF]

dipole-dipole attractions

3

Which one of the following exhibits dipole-dipole attraction between molecules?

Cl₂, CF₄, SnF₃, SiS₂, BI₃

SnF₃

4

Of the following substances, only ________ has London dispersion forces as its only intermolecular force.

NH₃, CH₄, CH₃OH, H₂S, HI

CH₄

5

The dissolution of water in octane (C₈H₁₈) is prevented by ________.

hydrogen bonding between water molecules

IMF Properties

1

Which one of the following should have the lowest boiling point?

LiF, SiF₄, PCl₃, Cl₂S, CH₃COOH

SiF₄

2

Which statements about viscosity are true?
(i) Viscosity increases as temperature decreases.

(ii) Viscosity increases as molecular weight increases

(iii) Viscosity increases as intermolecular forces increase.

All

3

Which is false?

The heat of sublimation is equal to the sum of the heat of vaporization and the heat of freezing.

4

Vapor Pressure of a liquid

increases nonlinearly with increasing temperature

5

Of the following, a 0.1 M aqueous solution of ________ will have the highest freezing point.

sucrose

Calculations

1

The heat of fusion of water is 6.01 kJ/mol. The heat capacity of liquid water is 75.3 J/mol*K. The conversion of 50.0 g of ice at 0.00 °C to liquid water at 0.00°C requires ________ kJ of heat.

16.7

2

Calculate the molality of a 15.3% (by mass) aqueous solution of hydrochloric acid

4.95 m

3

Calculate the mole fraction of nitric acid of a 10.4% (by mass) aqueous solution of nitric acid.

3.21×10⁻²

4

A solution is prepared by adding 30.00 g of lactose (milk sugar) to 110.0 g of water at 55 °C. The partial pressure of water above the solution is ________ torr. The vapor pressure of pure water at 55 °C is 118.0 torr. The MW of lactose is 342.3 g/mol.

116.3

5

On a clear day at sea level, with a temperature of 25°C, the partial pressure of N₂ in air is 0.78 atm and the concentration of nitrogen in water is 5.3*10^-4 M. When the partial pressure of N₂ is ________ atm, the concentration in water is 4.3*10^-3 M

6.3

Chemists have Solutions!

1

An unsaturated solution is one that ________.

has a concentration lower than the solubility

2

A sample of potassium nitrate (49.0 g) is dissolved in 100 g of water at 100 °C, with precautions taken to avoid evaporation of any water. The solution is cooled to 30.0 °C and no precipitate is observed. This solution is ________.

supersaturated

3

Pairs of liquids that will mix in all proportions are called ________ liquids.

miscible

4

The principal reason for the extremely low solubility of NaCl in benzene (C₆H₆) is the ________

weak solvation of Na⁺ and Cl^- by C₆H₆

5

The solubility of MnSO₄ monohydrate in water at 20 °C is 70.0 g per 100.0 mL of water. A solution at 20 °C that is 0.401 M in MnSO₄ monohydrate is best described as a(n) ________ solution. The formula weight of MnSO₄ monohydrate is 168.97 g/mol.

unsaturated

This N That

1

What is the normal boiling point of this substance?

29

2

Which of the following substances is more likely to dissolve in CH₃OH?

CCl₄, CH₃CH₂OH, Kr, H₂, N₂

CH₃CH₂OH

3

Pressure has an appreciable effect on the solubility of ________ in liquids.

Gases

4

In a saturated solution of a salt in water, ________.

the rate of crystallization = the rate of dissolution

5

A solution is prepared by dissolving 23.7 g of CaCl₂ in 375 g of water. The density of the resulting solution is 1.05 g/mL. The concentration of Cl^- in this solution is ________ M.

1.12