C8. Acids, Bases & Salts

Question 1

Solubility in water - Nitrate salts

Answer 1

All are soluble

Question 2

Solubility in water - Ethanoate salts

Answer 2

All are soluble

Question 3

Solubility in water - Sodium, potassium & ammonium salts

Answer 3

All are soluble

Question 4

Solubility in water - Chloride, bromide & iodide salts

Answer 4

Not all are soluble

Insoluble: silver chloride, lead(II) iodide

Question 5

Solubility in water - Sulfate salts

Answer 5

Most are soluble

Insoluble: barium sulfate, lead(II) sulfate, calcium sulfate

Question 6

Solubility in water - Carbonate salts

Answer 6

Most are insoluble

Soluble: Sodium carbonate, potassium carbonate, ammonium carbonate

Question 7

Colours - Potassium, sodium, ammonium, aluminium, calcium, lead(II), zinc salts

Answer 7

Solid: white

Aqueous solution: colourless

Question 8

Colours - Carbonate, chloride, nitrate, sulfate salts

Answer 8

Solid: white

Aqueous solution: colourless (except for carbonate precipitates)

Question 9

Colours - Iron(II) salts

Answer 9

Solid: green

Aqueous solution: green

Question 10

Colours - Iron(III) salts

Answer 10

Solid: brown

Aqueous solution: yellow/brown

Question 11

Colours - Copper(II) salts

Answer 11

Solid: blue

Aqueous solution: blue

Question 12

Colours - Copper(II) carbonate

Answer 12

Solid: green

Aqueous solution: N/A (insoluble in water)

Question 13

Colours - Copper(II) oxide

Answer 13

Solid: black

Aqueous solution: N/A (insoluble in water)

Question 14

Solid zinc oxide - hot

Answer 14

Yellow

Question 15

Solid zinc oxide - cold

Answer 15

White

Question 16

Solid lead(II) oxide - hot

Answer 16

Brown

Question 17

Solid lead(II) oxide - cold

Answer 17

Yellow

Question 18

Chromate(VI) ion CrO42-

Answer 18

Yellow

Question 19

Dichromate(VI) ion Cr2O72-

Answer 19

Orange

Question 20

Manganate(VII) ion MnO4-

Answer 20

Purple

Question 21

Iron(II) ion

Answer 21

Green

Question 22

Iron(III) ion

Answer 22

Brown

Question 23

Copper(II) ion

Answer 23

Blue

Question 24

Flame test - Lithium ion

Answer 24

Flame colour: red

Question 25

Flame test - Sodium ion

Answer 25

Flame colour: yellow

Question 26

Flame test - Potassium ion

Answer 26

Flame colour: lilac/purple

Question 27

Flame test - Copper(II) ion

Answer 27

Flame colour: blue-green

Question 28

Preparation of salt - Why is it necessary to filter the mixture after mixing and stirring?

Answer 28

To remove the precipitate/residue

Question 29

Preparation of salt - What is the purpose of washing the precipitate?

Answer 29

To remove SOLUBLE impurities

Question 30

Preparation of salt - Why leave the precipitate in a warm oven?

Answer 30

To dry solid / to remove water