Chapter 13

This law shows that the solubility of a gas increases with pressure. Sgas is the solubility of the gas at a particular temperature. Pgas is the partial pressure of the gas above the liquid.

Which of the following options that correctly describe Henry's law for gases? Select all that apply. Sgas = kH x Pgas

Which of the following options correctly reflect the effect of a nonvolatile solute on the boiling point of a solution? Select all that apply.

Boiling point elevation occurs because the presence of a nonvolatile solute lowers the vapor pressure of the solvent. The lower the concentration of the nonvolatile solute, the higher the vapor pressure of the solution. The greater the concentration of the solute, the higher the boiling point will be. A solution boils at a higher temperature than the pure solvent.

A solution containing 1 mol of a strong electrolyte will have a(n) _____ effect on the colligative properties of the solution than 1 mol of a nonelectrolyte. A strong electrolyte will dissociate or ionize in aqueous solution, and therefore the total number of dissolved solute particles is _____ for 1 mol of a strong electrolyte than for 1 mol of a nonelectrolyte solute.

Greater;greater

Which of the following statements correctly describe the molality and molarity of a solution? Select all that apply. Multiple select question.

M must be calculated using the volume of the solution, not the volume of the solvent. Both molarity and molality express concentration in terms of moles of solute. For a dilute aqueous solution molality and molarity are nearly equal.

Most solids are _____ soluble in a particular solvent at higher temperatures than at lower temperatures, although there are some exceptions. The solubility of a gas in water will generally _____ as temperature increases. Multiple choice question.

More;decrease

Which of the following statements correctly relate the charge density of an ion to heat of hydration? Select all that apply.

As the charge on an ion increases and its radius decreases, its charge density will increase and so will the magnitude of the heat of hydration. An ion with a higher charge density has a more negative heat of hydration than an ion of similar size but lower charge.

Which of the following statements correctly describe the osmotic pressure (Π) of a solution? Select all that apply. Multiple select question.

Osmotic pressure increases with temperature. Osmotic pressure is directly proportional to the molarity of the solution.

Which of the following statements correctly describe the heat of solvation for a solution process? Select all that apply.

The heat of solvation is called the heat of hydration if H2O is the solvent. The heat of solvation is the enthalpy change that occurs when a solute particle is surrounded by solvent particles. If ΔHhydr < 0, then more energy is released due to solvent-solute attraction than the energy absorbed in separating solvent particles.

Which of the following options correctly describe a solution that is in contact with undissolved solute at a given temperature? Select all that apply.

The rate at which solute is dissolving is equal to the rate at which solute particles are crystallizing from solution. The concentration of dissolved solute will not change. Undissolved solute is in equilibrium with dissolved solute.

Which of the following statements correctly describe the vapor pressure of a solution containing a volatile nonelectrolyte solute? Select all that apply.

The vapor pressure of each volatile component can still be calculated using PA = XAPoA. The vapor pressures of both volatile components will be lowered. The fraction of the volatile component in the vapor will be greater than that in the solution.

Which of the following options correctly describe the effect of temperature on the solubility of a solid in a given solvent? Select all that apply.

There is no clear correlation between ΔHsoln and solubility at different temperatures. In general, solids are more soluble at higher temperatures than at lower temperatures.

Freezing point _____ is observed for solutions containing nonvolatile solutes. The vapor pressure of a solution is _____ than that of the pure solvent, and the solution therefore freezes at a _____ temperature.

depression, lower, lower

Henry's law states that the solubility of a ______ in a solvent is directly proportional to the ______.

gas; pressure of that gas above the solution

A solution containing a nonvolatile solute always boils at a _____ temperature than the pure solvent. The vapor pressure of the solution is _____ than the vapor pressure of the pure solvent; hence the solution must be heated to a _____ temperature in order for the vapor pressure to equal the external pressure.

higher; lower; higher

The charge density of an ion has a significant effect on its heat of hydration. The _____ the charge on an ion and the _____ its size, the greater its attraction to the H2O molecules surrounding it and the more _____ the value of ΔHhydr of the ion.

higher; smaller; negative

The ratio mol of soluteL of solutionmol of soluteL of solution is called the _____ of a solution (symbol M), whereas the _____ (symbol m) of the solution is expressed as mol of solutekg of solventmol of solutekg of solvent. For an aqueous solution, these two quantities will be very similar if the solution concentration is _____. Multiple choice question.

molarity; molality; low

In an ideal solution of a strong electrolyte, the van't Hoff factor i is equal to _____. Multiple choice question.

the number of moles of particles produced by dissociation of 1 mol of the electrolyte

What are the features of a nonvolatile, nonelectrolyte solute? Select all that apply. Multiple select question.

A solute that has a negligible vapor pressure at the boiling point of the solvent A solute that dissolves but produces no ions in solution

Which step(s), involved in the formation of a solution, is/are associated with a positive sign for ΔH? Select all that apply.

Solute particles separate from each other. Solvent particles separate from each other.

Which of the following statements correctly explain the effect of a nonvolatile solute on the vapor pressure of a solution? Select all that apply.

The entropy of the solution is higher than that of the pure solvent. Solvent has less tendency to vaporize, and the vapor pressure is lowered. Solute particles on the solution surface decrease the number of solvent particles that can escape. Vapor pressure is lowered.

Which of the following statements correctly describe freezing point depression for a solution? Select all that apply.

The freezing point constant Kf is characteristic of the solvent. Freezing point depression is proportional to the molality of the solution. ΔTf is a positive value.

Which of the following options correctly describe the different ways of expressing the concentration of a solution? Select all that apply.

The unit for molality (symbol m) is mol/kg. To calculate mole fraction for a given mass of a reactant or product, the masses of all solution components must be known.

Which of the following statements correctly describe the enthalpy changes associated with the formation of a solution? Select all that apply.

Energy is released when the solvent and solute particles attract each other and mix to form a solution. Energy is absorbed to separate the solvent particles from each other. The overall enthalpy change for the solution process depends on the balance of energy absorbed vs. energy released.

Which of the following statements correctly describe entropy? Select all that apply.

Entropy is related to the number of ways a system can disperse its energy. The entropy of a gas is higher than the entropy of a liquid. Entropy is related to the freedom of motion of the particles in a system.

Which of the following statements correctly defines colligative properties?

Properties of a solution that depend only on the number of dissolved solute particles

Which of the following are applications of freezing point depression? Select all that apply.

Refining petroleum "Salting" frozen roads Biological antifreeze Car antifreeze

Which of the following are applications of osmotic pressure? Select all that apply.

Regulation of bodily water volume Food preservation Safe delivery of nutrients or drugs intravenously Absorption of water in trees