Chapter 13

Question 1

Define solvent

Answer 1

The majority component of a solution

Question 2

Define solute

Answer 2

The minority component of a solution

Question 3

What is spontaneous mixing and which way does water flow?

Answer 3

The tendency for soultions of different concentrations to mix when they come in contact. Water flows from less concentrated to more concentrated solution

Question 4

For a liquid solution, the solvent is always ________

Answer 4

Liquid

Note: solue may be gas, liquid, or solvent

Question 5

What factors determine solubility?

Answer 5

1. Nature’s tendency toward mixing
2. Intermolecular forces

Question 6

Define entropy

Answer 6

Measure of energy dispersal in a system

Question 7

When do solutions form and when do they not form?

Answer 7

When the solute-to-solvent attractions are weaker than the sum of the solute-to-solute and solvent-to-solvent attractions, the solution will form only if the energy difference is small enough to be overcome by the increase in entropy from mixing.

Question 8

For make a solution, you must overcome what?

Answer 8

1. all solute-solute attractive forces (endo +)

and

2. some solvent-solvent attractive forces (endo +)
3. Form new attractions between solute-solvent molecules (exo -)

ΔHsol’n = ΔHsolute + ΔHsolvent + ΔHmix

Question 9

Define miscible

Answer 9

Two liquids that are always solube in each other

Miscible - Alcohol and water

Immiscible - Oil and water

Question 10

What is solubility and what does it depend on?

Answer 10

Max amound of solute that can be dissolved in a given amount of solvent. Depends on Temperature and Pressure

Question 11

What is dynamic equilibrium?

Answer 11

What rate of dissolution (dissolving) = rate of deposition (recrystalization)

Question 12

What is ΔH_solution for aqueous solutions of ionic compunds?

Answer 12

ΔH_solution = ΔHhydration - ΔH_lattice

*ΔHsolute = - ΔH_lattice

*ΔHhydration = ΔH_solvent + ΔH_mix

Question 13

What is a solution considered saturated?

Answer 13

At the point of dynamic equilibrium

*Unsaturated < saturated

*Supersaturated > saturated

Question 14

For most solids, how are solubility and temperature related?

Answer 14

As Temperature increases, Solubility increases

Question 15

For gases, how are solubility and temperature related?

Answer 15

For ALL gases, as temperature increases, solubility decreases

Question 16

For gases, how are solubiliy and pressure related?

Answer 16

For ALL gases, as pressure increases, solubility increases

Note: Liquids/Solids are independent of pressure

Question 17

What is Henry’s Law?

Answer 17

S_gas = k_HP_gas

_{<span>Solubiilty of a gas is directly proportional to its partial pressure</span>}

Question 18

What are colligative properties?

Answer 18

Values depond ONLY on number of solute particles

Question 19

The vapor pressure of a solvent above a solution is _____than the vapor pressure of the pure solvent.

Answer 19

Lower

Question 20

Addition of a nonvolatile solute _____ the rate of vaporization, _____ the amount of vapor

Answer 20

reduces, decreasing

Question 21

What is Raoult’s Law?

Answer 21

P_{solvent in solution} = χ_solvent • P°

Question 22

What is the difference between a volatile and nonvolatile solute?

Answer 22

A volatile solute will contribute to the vapor pressure, a nonvolatile solute will not contribute to vapor pressure.

Question 23

What is Raoult’s Law for a Volatile Solute?

Answer 23

Ideal solution (similar structure eg. polar-polar)

P_total = P_solute + P_solvent

Question 24

What is the difference between Ideal and Nonideal Solutions?

Answer 24

Ideal: solute-solvent interations = solute-solute + solvent-solvent

Nonideal: solue-solvent < or > solute-solute + solvent-solvent

Question 25

For a nonideal solution, when the solute–solvent interactions are stronger than the solute–solute + solvent–solvent, the total vapor pressure of the solution will be ______ than predicted by Raoult’s law

Answer 25

less than

Question 26

For a nonideal solution, when the solute–solvent interactions are weaker than the solute–solute + solvent–solvent, the total vapor pressure of the solution will be _____ than predicted by Raoult’s law.

Answer 26

greater

Question 27

For freezing point depression, what is ΔT_f

Answer 27

FP_solvent – FP_solution

Question 28

For boiling point elevation, what is ΔT_b

Answer 28

BP_solution – BP_solvent

Question 29

Define osmosis

Answer 29

Flow of solvent (water) from area of low concentration to area of high concentration

Question 30

A semipermeable membrane allows what to flow through it?

Answer 30

**Solvent**, not solute

Question 31

A negative deviation of Raoult's law (Strong solute-solvent) results from a \_\_\_\_\_-\_\_\_\_\_ interaction

Answer 31

Polar-Polar

Question 32

A positive deviation of Raoult's law (Weak solute-solvent) results from a \_\_\_\_\_-\_\_\_\_\_ interaction

Answer 32

Polar-Nonpolar

Question 33

An ideal solution that follows Raoult's law results from a \_\_\_\_\_-\_\_\_\_\_ interaction

Answer 33

Nonpolar-Nonpolar

Question 34

What would result in a larger orientation factor (p)?

Answer 34

**Symmetric** molecules (H₂) Means that more molecules have correct orientation that allows them to react with one another.