- Chemical Tests

Question 1

Hydrogen

Answer 1

Lit splint makes a squeaky pop

Question 2

Oxygen

Answer 2

Relights glowing splint

Question 3

Carbon Dioxide

Answer 3

• Bubble through limewater

- Turns milky (white precipitate of CaCO3)

Question 4

Carbonates

Answer 4

• React with acids

- Effervescence, CO2 test

Question 5

Sulfates

Answer 5

• Add barium chloride

- White precipitate of barium sulfate

Question 6

Cu2+ ion

Answer 6

• Add dilute sodium hydroxide

- Blue, gelatinous precipitate of Cu(OH)2

Question 7

Fe2+ ion

Answer 7

• Add dilute sodium hydroxide

- Green, gelatinous precipitate of Fe(OH)2

Question 8

Fe3+

Answer 8

• Add dilute sodium hydroxide

- Rust-brown, gelatinous precipitate of Fe(OH)3

Question 9

Alcohols

Answer 9

• Add potassium dichromate and sulfuric acid

- Orange to green

Question 10

Alkenes

Answer 10

• Add bromine

- Orange to colourless

Question 11

Ammonia/Ammonium Salts

Answer 11

• Damp red litmus paper

- Turns blue

Question 12

Halide ions

Answer 12

• Add silver nitrate
• Chlorine -> white
• Bromine -> cream
• Iodine -> yellow

Question 13

NH4+ ions

Answer 13

• Add aqueous OH-

- Ammonia produced (damp red litmus paper turns blue)