EXAM 2 chapter 13b

Question 1

if total energy for breaking attractions btw particles (in pure solute and pure solvent) is less than

Answer 1

the energy released in making the new attractions btw the solute and solvent than the overall process will be EXOTHERMIC

Question 2

if total energy for breaking attractions btw particles (in pure solute and pure solvent) is greater than

Answer 2

energy released in making new attractions btw solute and solvent than overall process will be ENDOTHERMIC

Question 3

in two cases the enthalpy of solution is expected to be small and neg/pos

Answer 3

the entropic contributions dominate and the solution forms readily (ΔG <0)

Question 4

in other two cases the enthalpy of solution is expected to be large and positive

Answer 4

entropic contribution is typically too small to overcome the enthalpy term and solution won’t form ( ΔG>0)

Question 5

solution process starts by solute particles surrounded by solvent particles and

Answer 5

and solute particles begin to decrease over time

Question 6

at some point there is high enough concentration of solute particles that they will

Answer 6

precipitate when they bump into each other

Question 7

at the point rate of dissolution(dissolving)=rate of crystallization then solution

Answer 7

is in dynamic equilibrium

Question 8

saturated means a solution that

Answer 8

has the solute and solvent in dynamic equilibrium

Question 9

a saturated solution is one that contains

Answer 9

the max possible amount of dissolved solute at equilibrium at that temp (add more solute-it won’t dissolve, and solute concentration won’t change at that temp)

Question 10

saturation concentration depends on

Answer 10

temperature and pressure

Question 11

supersaturated is when a solution

Answer 11

that has more solute than saturation

Question 12

supersaturation can be achieved by

Answer 12

increasing the temperature, dissolving more solute and then bringing the temp back down

Question 13

a solution that has less solute than saturation is

Answer 13

unsaturated

Question 14

supersaturated solutions are

Answer 14

unstable (excess solute precipitates out of solution normally)

Question 15

solubility of most solid solutes in water increases as

Answer 15

solution temp increases

Question 16

impact of temp changes depends on

Answer 16

enthalpy of solution

Question 17

change in enthalpy of solution is exothermic then

Answer 17

decreasing the temperature will increase solubility

Question 18

change in enthalpy of solution is endothermic then

Answer 18

increasing temperature increases solubility

Question 19

solubility of gas increases with

Answer 19

decreasing temperature

Question 20

solubility of gas depends on

Answer 20

pressure

Question 21

as pressure of gas increases

Answer 21

solubility of gas increases