Heat Capacity, Phase Changes, and Colligative Properties

Question 1

phase

Answer 1

any part of a system that is homogeneous

Question 2

heat capacity

Answer 2

the added energy required to increase the temp of that substance by one degree

Question 3

constant pressure heat capacities _____ than constant volume heat capacities

Answer 3

greater than

Question 4

q =

Answer 4

C(delta)T

mc(delta)T

Question 5

c_water =

Answer 5

1 cal g^-1 C^-1

Question 6

calorimeter

Answer 6

device which measures energy change

Question 7

coffee cup calorimeter

Answer 7

constant pressure calorimeter, measures energy change at atmospheric pressure, used to measure heats of reaction

Question 8

bomb calorimeter

Answer 8

measures energy change at constant volume, tell internal energy change in reaction

Question 9

heat of fusion

Answer 9

enthalpy change associated with melting

Question 10

heat of vaporization

Answer 10

enthalpy change associated with boiling

Question 11

each phase of a substance has its own ___

Answer 11

specific heat

Question 12

solid to gas phase change

Answer 12

sublimation

Question 13

gas to solid phase change

Answer 13

deposition

Question 14

melting, boiling/vaporization, and sublimation normally increase ….

Answer 14

increase volume and molecular motion, increased system entropy
entropy and enthalpy both positive

Question 15

entropy and enthalpy are negative for…

Answer 15

freezing, condensation, and deposition

Question 16

phase diagram

Answer 16

indicates phases of a substance at different pressures and temperatures, each section represents different phase, boundary lines represent temps and pressures where the corresponding phases are in equilibrium with each other

Question 17

triple point

Answer 17

the one point where a substance can exist in equilibrium as a solid, liquid, and gas

Question 18

critical temperature

Answer 18

temperature above which a substance cannot be liquified regardless of pressure applied

Question 19

critical pressure

Answer 19

pressure required to produce liquefaction while the substance is a the critical temperature

Question 20

critical point

Answer 20

critical temp and pressure define

Question 21

colligative properties

Answer 21

properties that depend solely on the number of particles, irrespective of the type of particles
4 colligative properties of solutions: vapor pressure, boiling point, freezing point, osmotic pressure

Question 22

boiling point elevation equation

Answer 22

boiling point elevation of an ideally dilute solution due to the addition of a nonvolatile solute

(delta)T = k(_b)mi

k(_b) = specific constant of substance being boiled
m = molality of solution 
i = van't Hoff factor

Question 23

van’t Hoff factor

Answer 23

number of particles into which a single solute particle will dissociate when added to solution
2 possible values: expected value and observed

Question 24

substance boils when…

Answer 24

its vapor pressure equals the local atmospheric pressure

Question 25

freezing point depression for an ideally dilute solution

Answer 25

(delta)T = K(_f)mi

freezing point depression with addition of non-volatile solute

Question 26

molality ____ change with temperature while molarity____

Answer 26

molality does not change with temp, molarity does

Question 27

osmotic pressure

Answer 27

measure of the tendency of water (or other solvent) to move into a solution via osmosis,
pressure pulling into a solution
= iMRT

M is molarity of solution