Chapter 13

Question 1

How a solution is formed

Answer 1

• When one substance disperses uniformly throughout another
• When the magnitudes of the attractive forces between solute and solvent particles are comparable to or greater than those that exist between the solute particles themselves or between the solvent particles themselves.

Question 2

Ability of substance to form solutions depends on 2 general factors

Answer 2

1) the types and relative strengths of intermolecular interactions between and among solute and solvent particles
2) natural tendency of substances to spread into larger volumes when not restrained

Question 3

Ion-dipole forces dominate (when?)

Answer 3

Solutions consist of ionic substances in water

Question 4

Dispersion forces dominate (when?)

Answer 4

Nonpolar substance dissolves in another nonpolar one.

Question 5

How to identify a solvent

Answer 5

Normally the component present in the greatest amount

Question 6

How to identify a solute

Answer 6

Other components in a solution other than the solvent (which is ththe greatest quantity)

Question 7

Gas + Gas =

Answer 7

Gas

Question 8

Liquid + Gas =

Answer 8

Liquid

Question 9

Liquid + Liquid =

Answer 9

Liquid

Question 10

Liquid + Solid =

Answer 10

Liquid

Question 11

Solid + Gas =

Answer 11

Solid

Question 12

Solid + Liquid =

Answer 12

Solid

Question 13

Solid + Solid =

Answer 13

Solid

Question 14

Entropy

Answer 14

The degree of randomness in a system (disorder).

Question 15

Crystallization

Answer 15

When a solution reforms into solvent; when particles of solute reattach to a solid.

Question 16

Saturation

Answer 16

A solution in equilibrium with undissolved solute

Question 17

Solubility

Answer 17

The amount of solute needed to form a saturated solution in a given quantity of solvent, at a specified temperature.

Question 18

Unsaturated solution

Answer 18

Less solute is dissolved than that needed to form a saturated solution

Question 19

Supersaturation

Answer 19

Solutions with more solute than that needed to form a saturated solution (unstable condition).

Question 20

Effect of increasing molecular mass or polarity on solubility

Answer 20

Solubility increases with increasing molecular mass or polarity

Question 21

The stronger the attractions are between solute and solvent molecules, the greater/lesser the solubility

Answer 21

Greater

Question 22

Polar liquids tend to dissolve readily in polar solvents because

Answer 22

of favorable dipole-dipole attractions between solvent molecules and solute molecules.

Question 23

Miscible

Answer 23

Pairs of liquids that mix in all proportions

Question 24

Immiscible

Answer 24

Liquids that do not dissolve in one another

Question 25

Nonpolar liquids tend to be insoluble in polar liquids because

Answer 25

the attraction between the polar water molecules and the nonpolar hydrocarbon molecules is not sufficiently strong to allow the formation of a solution.

Question 26

What does "like dissolves like" mean?

Answer 26

Substances with similar intermolecular attractive forces tend to be soluble in one another.

Question 27

Solubilities of solids and liquids are/are not appreciably affected by pressure

Answer 27

Are not

Question 28

Solubility of gases are/are not appreciably affected by pressure

Answer 28

Are

Question 29

Effect of pressure on solubility of gas

Answer 29

Solubility of the gas increases in direct proportion to its partial pressure above the solution

Question 30

Henry's law

Answer 30

``` Sg = kPg Sg = solubility of the gas in the solution phase (expressed as molarity) Pg = partial pressure of the gas over the solution k = proportionality constant called Henry's law constant ```

Question 31

what is Henry's law constant?

Answer 31

Different for each solute-solvent pair | Varies with temperature

Question 32

Effect of temperature on solubility of solids

Answer 32

The solubility of most solid solutes in water increases as the temp increases

Question 33

Effect of temperature on solubility of gases

Answer 33

Solubility of gases in water decreases with increasing temp

Question 34

Mass % formula

Answer 34

g solute/g solution * 100 | Also, g solute/(g solute + g solvent)

Question 35

Mole fraction

Answer 35

mol solute/mol solution Also, mol solute/(mol solute + mol solvent) -Moles of component/total moles of all components

Question 36

Molarity (M)

Answer 36

mol solute/L solution

Question 37

Molality (m)

Answer 37

mol solute/kg solvent

Question 38

How to convert m (molality) to mole fraction

Answer 38

convert kg of solvent to mol of solvent and use the above formula

Question 39

What is the conversion factor between molarity and molality?

Answer 39

density of the solution (g/L)

Question 40

Colligative propertios

Answer 40

Boiling point, freezing point, vapor pressure (skipping calculations for test), osmotic pressure

Question 41

Normal boiling point

Answer 41

Temp at which a liquid's vapor pressure will equal 1 atm

Question 42

Boiling point elevation equation

Answer 42

Delta-Tb = Kb x Cm (or, Kb x m) (change in temp = molal bpe constant, times the molality of the solution) Also, Delta-Tb = Tb solution - Tb solvent

Question 43

Freezing point depression equation

Answer 43

Delta-Tf = Kf x Cm (or, Kb x m) (change in temp = molal fpd constant, times the molality of the solute) Also, Delta-Tb = Tb solvent - Tb solution

Question 44

Osmotic Pressure (definition)

Answer 44

Pressure difference at equilibrium; the applied pressure required to prevent the net movement of water from solute to solution (prevent osmosis by pure solvent)

Question 45

Osmotic Pressure equation

Answer 45

II = MRT | Molarity, times the ideal-gas constant, times temp (K)