Section 12.4- Colligative Properties

Question 1

any property that depends on the number of particles and not on the identity or properties of the particles is a

Answer 1

colligative property

Question 2

important colligative properties

Answer 2

1. vapor pressure lowering
2. freezing point depression
3. boiling point elevation
4. osmotic pressure

Question 3

vapor pressure is a

Answer 3

dynamic equilibrium (rate of condensation and rate of evaporation are equal)

Question 4

at equilibrium the number of molecules evaporating and the number of molecules condensing are

Answer 4

EQUAL

Question 5

the pressure exerted by the vapor when a liquid phase and vapor phase are in equilibrium is the

Answer 5

vapor pressure

Question 6

may be considered a measure of the escaping tendency of molecules in the liquid

Answer 6

vapor pressure

Question 7

the higher the vapor pressure, the easier it is for

Answer 7

a liquid to escape and become a gas

Question 8

the lower the vapor pressure, the harder it is for

Answer 8

liquid to escape and become a gas

Question 9

a gas is highly influenced by

Answer 9

temperature and pressure

Question 10

the higher the temperature, the higher the

Answer 10

vapor pressure

Question 11

the addition of a nonvolatile solute to a solvent _________________ the tendency of the solvent molecules to escape from the surface of the liquid

Answer 11

reduces

Question 12

a nonvolatile solute _______________ the vapor pressure of the solvent

Answer 12

lowers

Question 13

using a nonvolatile solute lowers the vapor pressure requires a

Answer 13

higher temperature to boil

Question 14

the vapor pressure lowering has an effect on

Answer 14

both the boiling and freezing points of the solution

Question 15

the lowering of vapor pressure in solutions is a

Answer 15

colligative property

Question 16

the temperature at which the vapor pressure of the liquid equals the atmospheric pressure

Answer 16

boiling point of a liquid

Question 17

if the atmospheric pressure is 1 atm, the temperature is the

Answer 17

normal boiling point

Question 18

the boiling point when a nonvolatile solute is present is

Answer 18

boiling point elevation (delta Tb)

Question 19

the temperature at which the vapor pressures of the solid and liquid are equal

Answer 19

freezing point

Question 20

the resulting phenomenon when the vapor pressure is lowered due to the presence of a solute and in turn lowers the freezing point of the solvent

Answer 20

freezing point depression (delta Tf)

Question 21

boiling point elevation and freezing point depression are

Answer 21

colligative properties

Question 22

constant values are associated with each solvent and known as the

Answer 22

molal boiling point elevation constant (Kb)
molal freezing point depression constant (Kf)

Question 23

equation for the constants of freezing and boiling

Answer 23

delta Tb= mKb
delta Tf= mKf

Question 24

to find the actual boiling point or freezing point of a given solution, the freezing point depression must be ________________ the normal freezing point, and the boiling point elevation must be _____________________ the normal boiling point

Answer 24

*subtracted from (normal freezing point - freezing point depression)

*added to (boiling point elevation + normal boiling point)

Question 25

substances that do not ionize or dissociate in aqueous solutions to produce ions that can conduct an electrical current are

Answer 25

nonelectrolytes

Question 26

compounds that dissolve in water to produce ions that can conduct electrical current are

Answer 26

electrolytes

Question 27

dissociate or ionize essentially completely in water to give solutions that are good conductors

Answer 27

strong electrolytes

Question 28

are generally polar covalent substances that do not dissociate completely in water and whose solutions are poor conductors of electricity

Answer 28

weak electrolytes

Question 29

various substances that permit the passage of some molecules but not others are said to be

Answer 29

semipermeable membranes

Question 30

the more __________- present, the more effective electroconductibity

Answer 30

ions

Question 31

occur since the solvent is more concentrated on the side of the membrane containing pure water and more collisions per unit time by solvent molecules occur there, resulting in a net flow of water into the solution

Answer 31

osmosis

Question 32

the pressure exerted on the membrane due to the hydrostatic pressure on the solution forcing solvent from the solution into the pure solvent at the same rate that is flows in the reverse direction

Answer 32

osmotic pressure

Question 33

the direction of the solvent flow is always from the more ______________ solution to the more _____________ concentrated solution

Answer 33

more dilute to more concentrated

Question 34

used to desalinate water

Answer 34

reverse osmosis