Kaplan Chemistry: Chapter 9 Solutions

Question 1

what is solvation

Answer 1

electrostatic interaction between solute and solvent molecules

Question 2

when electrostatic interations are stronger than the original ones in the reactants, the solvation energy is ____

Answer 2

exothermic.

Question 3

when the new interactions are weaker than the original interactions int he reactiants, the solvation is ___

Answer 3

nedothermic.

Question 4

trend of entropy upon dissolution

Answer 4

at contant temp and pressure, entropy always increases upon dissolution.

Question 5

what is the solubility of a spontaneous dissolution reaction

Answer 5

if G is negative, than the reaction is spontaneous and the solute is soluble.

Question 6

percent composition by mass formula

Answer 6

(mass solute/mass of solution)x 100

Question 7

molality

Answer 7

moles of solute/kg of solvent.

Question 8

what entity is used to calculate boiling point elevation and freezing point depression?

a. molarity
b. molality
c. normality
d. molefraction

Answer 8

molALITY.

Question 9

dilution equation

Answer 9

c1v1 = c2v2

Question 10

how can solubility of gases be increased?

Answer 10

solubility of gases can be increased by DECREASING the temp and INCREASING the partial pressure of the gas above the solvent (henry’s law)

Question 11

if an anion is insoluble in neutral water, but, dissolves in an acidic solution, the anion is most likely ___

Answer 11

basic.

Question 12

___ pressures favor the dissolution of gas solutes

Answer 12

High pressure

Question 13

in solution chemistry, Q is the “equilibrium “ constant. What is it also known as?

Answer 13

ion product constant

Question 14

high vapour pressure = ___ evaporates

Answer 14

easily evaporates

Question 15

t/f colligatie properties are dependent on the identity of the chemical

Answer 15

FALSE. they are only dependent on the concentration of the dissolved particles.

Question 16

name the colligative properties (4)

Answer 16

1) vapour pressure
2) boiling point
3) freezing point depression
4) osmotic pressure.

Question 17

raoults law

Answer 17

as solute is added to the solvent, the vapour pressure DECREASES. This is because it is harder for solvent particles to interact with one another. therefore, solute moelcules can BLOCK evaporation of the solvent by decreasing their vapour pressure.

Question 18

boiling point elevation is when vapour pressure =

Answer 18

ambient pressure.

Question 19

as solute is added to the solvent, the boiling point __

Answer 19

increases. a BP is the temp where CP = ambient pressure. if VP of a solution is lower than that of the pure solvent, then more energy will be required before its vapor pressure = ambient pressure.

Question 20

equation for boiling point elevation

Answer 20

Tb = iKbm
m= molality

Question 21

which colligative property of a substance will give the best estimate of its relative vapour pressure?

Answer 21

boiling point elevation.

Question 22

as solute is added to the solvent, the freezing point ____

Answer 22

decreases. this is known as freezing point depression .this occurs because solute particles interferes with the formation of lattice structures.

Question 23

T/F: osmotic pressure also uses molality.

Answer 23

false. only freezing point depression and boiling point elevation uses molality (mol solute /kg of solvent). osmotic pressure = iMRT. M is MOLARITY (concentration).

Question 24

the higher the molarity of the solute, the ___ osmotic pressure

Answer 24

MORE osmotic pressure

Question 25

the higher the molarity of the solvent, the ___ osmotic pressure

Answer 25

LESS osmotic pressure. the solute is diluted in a lot of solvent.

Question 26

a faraday is equal to one mole of:

Answer 26

electric charge.
ex/ because an aluminum ion gains 3 electrons 0.1 faraday of charge will reduce 0.1/3 moles of aluminum, or 0.033 mols of aluminum