2h. Chemical Tests

Question 1

Test (T) + Result (R) for: Hydrogen

Answer 1

(T) Lit splint.
(R) Hear a squaky POP

Question 2

Test (T) + Result (R) for: Oxygen

Answer 2

(T) Glowing splint.
(R) Glowing splint relights

Question 3

Test (T) + Result (R) for: Carbon Dioxide

Answer 3

(T) Bubble the gas through limewater
(R) Limewater turns cloudy

Question 4

Test (T) + Result (R) for: Ammonia

Answer 4

(T) Red litmus paper
(R) Turns damp red litmus paper blue

Question 5

Test (T) + Result (R) for: Chlorine

Answer 5

(T) Damp litmus paper
(R) Turns damp litmus paper white (bleaches)

Question 6

How to carry out a flame test:

Answer 6

• A platinum or nichrome wire is dipped into concentrated hydrochloric acid to remove any impurities.
• The wire is dipped into the salt being tested so some salt sticks to the end.
• The wire and salt are held in a non-luminous (roaring) bunsen burner flame.
• The colour is observed.

Question 7

Colour of the flame for: Lithium

Answer 7

Red

Question 8

Colour of the flame for: Sodium

Answer 8

Yellow

Question 9

Colour of the flame for: Potassium

Answer 9

Lilac

Question 10

Colour of the flame for: Calcium

Answer 10

Orange-red

Question 11

Colour of the flame for: Copper (II)

Answer 11

Blue-green

Question 12

If chloride ions are present:

Answer 12

White precipitate of silver chloride will form

Question 13

If bromide ions are present:

Answer 13

Cream precipitate of silver bromide will form

Question 14

If iodide ions are present:

Answer 14

Yellow precipitate of silver iodide will form

Question 15

If sulfate ions are present:

Answer 15

White precipitate of barium sulphate will form

Question 16

If carbonate ions are present:

Answer 16

Fizzing will occur

Question 17

If water is present…

Answer 17

Anhydrous copper (II) sulfate will change from white to blue.

Question 18

How do you know if a sample is pure water

Answer 18

It will boil at 100 degrees Celsius