Chapter 14 Aqueous solutions

Question 1

solubility

Answer 1

the amount of solute that can be dissolved in a given quantity of solvent

Question 2

solute

Answer 2

a substance that dissolves in a solvent
eg. sugar (solute) in water (sugar)

Question 3

solvent

Answer 3

a substance which is able to dissolve a solute to form a solution

Question 4

solution

Answer 4

a homogenous mixture of solute dissolved in a solvent
eg. water and sugar

Question 5

saturated

Answer 5

no more solute can be dissolved at a particular temperature

Question 6

unsaturated

Answer 6

more solute may be dissolved at a particular temperature

Question 7

supersaturated

Answer 7

an unstable solution that contains more dissolved solute than a saturated solution

Question 8

Solubility curves

Answer 8

represents a relationship between solubility and temp.

Question 9

above the curve

Answer 9

represents a supersaturated solution

Question 10

on the curve

Answer 10

saturated solution

Question 11

below the curve

Answer 11

unsaturated solution

Question 12

NAG SAG
LMS
CASTROBEAR

Answer 12

nitrates (NO3–)
acetates (CH3COO–)
group 1
sulfates (SO42-) ◊ ©
ammonium (NH4+)
group 17 ◊

Exceptions – LMS and CASTROBEAR

LMS (noted as ◊ above)

Lead (Pb2+),
Mercury (Hg2+),
Silver (Ag+)

CASTROBAR (noted as © above)

Calcium (Ca2+),
Strontium (Sr2+),
Barium (Ba2+)

Question 13

When does crystallisation occur?

Answer 13

when an unsaturated solution becomes saturated in crystals form

Question 14

Variables affecting crystal growth

Answer 14

Rates of cooling
rate of evaporation
nucleation

Question 15

concentrated solutions

Answer 15

A concentrated solution is one that has a relatively large amount of dissolved solute

Question 16

diluted solutions

Answer 16

a relatively small amount of dissolved solute.

Question 17

Concentration in grams per litre (g per L)

Answer 17

concentration in g/L= mass of solute (g)/volume of solution (L)

Question 18

Concentration in parts per million (ppm)

Answer 18

concentration (ppm)= mass of solute (mg)/ mass of solution (kg)

Question 19

Concentration in milligrams per litre (mg per L)

Answer 19

concentration mg/L=mass of solute (mg)/volume of solution (L)
same as ppm

Question 20

Concentration in parts per billion (ppb)

Answer 20

concentration ppb=mass of solute (micrograms)/mass of solution (Kg)

Question 21

percentage by mass (m/m)

Answer 21

Mass percent = (mass of chemical (g)/ total mass of compound(g)) x 100

Question 22

percentage by volume (v/v)

Answer 22

Volume Percent=Volume of Solute (mL)/Volume of Solution (mL)×100%

Question 23

percentage mass/volume (m/v)

Answer 23

mass of solute (g)/ volume of solution (mL) × 100

Question 24

Concentration in moles per litre

Answer 24

c=n(in mol) /v(L)

Question 25

Questions involving dilution

Answer 25

c1V1=c2V2