Chapter 12: Solutions (sections 1 & 2)

Question 1

the composition of a solution is expressed as

Answer 1

concentration

Question 2

conentration is always expressed as the quantity of .. present in a fixed quantity of the … or …

Answer 2

solute; solution; solvent

Question 3

for most solutes, there is a limit to the quntity that can dissolve in a

Answer 3

fixed volume of a given solvent

Question 4

the solubility of a solute is reached when the …. and the …. are equal

Answer 4

rate of dissolution; rate of crystallization

Question 5

solubility is the concentration of solute that exists in equilibrium with an ….; that is, it is the maximum concentration that can … at a particular temperature

Answer 5

excess of that substance; dissolve

Question 6

a saturated solution is one that is in equilibrium with

Answer 6

an excess of the solute

Question 7

the concentration of a saturated solution is equal to the

Answer 7

solubility

Question 8

an unsaturated solution is one in which the concentration of the solute is

Answer 8

less than the solubility

Question 9

supersatured solutions have a concentration of solute that is

Answer 9

temporarily greater tahn its solubility

Question 10

supersaturation is an … condition

Answer 10

unstable

Question 11

two of the most important factors that determine whether a given substance will dissolve in a solvent include:

Answer 11

the enthalpy change that accompanies solute-solvent interactions
change in disorder

Question 12

three types of intermolecular forces are involved in the formation of condensed phase solutions:

Answer 12

solute-solute, solvent-solvent, solute-solvent

Question 13

(steps in solution formation) step 1 ΔH1: expanding the solute: separating the solute into

Answer 13

individual components; endothermic

Question 14

(steps in solution formation) step 2 ΔH2: expanding the solvent: overcoming …. of the solvent molecules

Answer 14

intermolecular forces ;endothermic

Question 15

(steps in solution formation) step 3 ΔH3: interaction of … and … to form the solution

Answer 15

solute; solvent; exothermic

Question 16

enthalpy of solution=

Answer 16

ΔH1 + ΔH2 + ΔH3

Question 17

heat of solution is the amount of heat energy absorbed or released when a

Answer 17

specific amount of solute dissolves in a solvent

Question 18

many substances with positive enthalpies of solution still dissolve … due to an increase in .. (…) which is favorable

Answer 18

spontaneously; entropy; disorder

Question 19

water surrounds ions in a

Answer 19

sphere of hydration

Question 20

disorder increases significantly when ionic solids

Answer 20

dissolve in solution

Question 21

the interaction of the ions with water molecules is called

Answer 21

hydration

Question 22

pressure has very little effect on the solubilities of .. and ..

Answer 22

solids; liquids

Question 23

the solubility of a gas is directly proportional to its …. at a …./ [a] is calculated via …

Answer 23

partial pressure; given temperature; henry’s law

Question 24

henry’s law:

Answer 24

C=kP

Question 25

an increase in pressure favors the

Answer 25

denser phase

Question 26

for gaseous solutes, an increase in pressure is relieved by additional

Answer 26

gas dissolving in the liquid

Question 27

le chatelier’s principle can be used to predict what is favored:
endothermic:
exothermic:

Answer 27

A + solvent + heat ↔ solution

B + solvent ↔ solution + heat

Question 28

as temperature increases, the solubility … for any substance with an endothermic enthalpy of solution and … for one with an exothermic enthalpy of solution

Answer 28

increases; decreases

Question 29

since the enthalpy of solution for most gases in water is exothermic their solubilities … with an increase in temperature

Answer 29

decrease

Question 30

the solubilities of most solids … as the temperature of the solution increases

Answer 30

increases

Question 31

some substances that appear to violate these generalizations undergo a more

Answer 31

complex dissolution process

Question 32

the rte at whcih solids dissolve …. with increasing surface area of the solid

Answer 32

increases

Question 33

solids tend to dissolve best when:

Answer 33

heated, stirred, ground into small particles

Question 34

gases tend to dissolve best when: the solution is …, … is high

Answer 34

cold; pressure