Testing for negative ions

Question 1

Carbonate (CO₃) - Test and result

Answer 1

1. Add a dilute acid (HCl).
2. Effeversence will occur.
3. Bubble the gas produced into limewater and if it goes cloudy then it is a carbonate.

Question 2

Chloride

Answer 2

White precipitate

Question 3

Bromide

Answer 3

Cream precipitate

Question 4

Iodide

Answer 4

Yellow precipitate

Question 5

Halide method

Answer 5

1. Add dilute nitric acid to remove carbonate ions.
2. Add silver nitrate solution and a precipitate of silver ions and halides ions will form.
3. Colours represent different halides.

Question 6

Sulfate

Answer 6

White precipitate

Question 7

Sulfate method

Answer 7

1. Add dilute hydrochloric acid to remove carbonate ions.
2. Add barium chloride solution and a precipitate of white barium sulfate will form.