Module 11

Question 1

Define solubility

Answer 1

the maximum amount of solute that can dissolve in a given amount of solvent

Question 2

solute

Answer 2

substance that we are dissolving

Question 3

solvent

Answer 3

substance we are dissolving the solute in

Question 4

solution

Answer 4

when the solute and solvent are mixed together

Question 5

requirements for dissolving a solid

Answer 5

solvent molecules must be attracted to the solute molecules so strongly that the solvent molecules can get between the solute molecules and pull them apart from each other

Question 6

requirements for dissolving a liquid

Answer 6

the solvent molecules need only be a little attracted to the solute molecules because the solvent does not need to separate the solute molecules very much, they only need to get between the solute molecules

Question 7

requirements for dissolving a gas

Answer 7

the solvent molecules must be attracted to the solute molecules enough to pull the solute molecules closer to one another

Question 8

the solubility of any solute depends on

Answer 8

the identity of the solute

the identity of the solvent

Question 9

saturated solution

Answer 9

a solution in which the maximum amount of solute has been dissolved

Question 10

precipitation

Answer 10

the process by which a solid solute leaves a solution and turns back into its solid phase

Question 11

for solid solutes, solubility usually – with increasing temp

Answer 11

increases

Question 12

solubility of — substances is not affected by temperature

Answer 12

liquid

Question 13

solubility of gases – with increasing temp

Answer 13

decreases

Question 14

increasing pressure – the solubility of –

Answer 14

increases; gases

Question 15

pressure does not affect solubility of – or –

Answer 15

liquids or solids

Question 16

exothermic process

Answer 16

a process that releases heat– becomes warm to the touch

Question 17

endothermic process

Answer 17

a process that absorbs heat– becomes cool to touch

Question 18

molality

Answer 18

number of moles of solute per Kg of solvent

Question 19

freezing point depression

Answer 19

when a solute is dissolved in a solvent the solution always has a lower freezing point than the pure solvent

Question 20

freezing point depression constant

Answer 20

physical constant that depends solely on the chemical nature of the solvent (Kf)

Question 21

Boiling point elevation

Answer 21

when a solute is dissolved in a solvent the boiling point of the resulting solution is higher than that of the pure solvent