Chemical / Gas Tests

Question 1

Hydrogen

Answer 1

Lit splint on test tube causes a squeaky pop.

Question 2

Carbon Dioxide

Answer 2

Add limewater to the gas. Will turn cloudy.

Question 3

Oxygen

Answer 3

Glowing splint on test tube. Will relight.

Question 4

Chlorine

Answer 4

Put damp red litmus paper into a test tube. Will turn white.

Question 5

Ammonia

Answer 5

Turns damp red litmus paper blue.

Question 6

Iron (II)

Answer 6

(Sodium hydroxide cation) Green precipitate

Question 7

Iron (III)

Answer 7

(Sodium hydroxide cation) Red/brown precipitate

Question 8

Copper (II)

Answer 8

(Sodium hydroxide cation) Blue precipitate

Question 9

NH4+ (Ammonium)

Answer 9

(Sodium hydroxide cation) NH3 (Ammonia) + Water

Question 10

Pottasium

Answer 10

(Flame test) Lilac

Question 11

Copper

Answer 11

(Flame test) Blue-Green

Question 12

Sodium

Answer 12

(Flame test) Yellow

Question 13

Calcium

Answer 13

(Flame test) Brick-red

Question 14

Lithium

Answer 14

(Flame test) Red

Question 15

Flame test steps

Answer 15

1. Put Nichrome wire in Hydrochloric acid
2. Place the loop in the sample, then the flame.
3. Observe the colour change.
   (Make sure the wire is clean, so the colour is accurate)

Question 16

Carbonate

Answer 16

Add acid, fizzes. Lime water turns milky.

Question 17

Sulfate

Answer 17

Add Hydrochloric acid and Barium Chloride, which goes to white precipitate.

Question 18

Chloride

Answer 18

(Add silver nitrate) White precipitate

Question 19

Bromide

Answer 19

(Add silver nitrate) Cream precipitate

Question 20

Iodide

Answer 20

(Add silver nitrate) Yellow precipitate

Question 21

Water test

Answer 21

Anhydrous Copper (II) Sulfate turns blue in the presence of water.