Tests for anions

Question 1

carbonate (CO3)

Answer 1

add dilute hydrochloric acid to the compound, observing for effervescence (bubbles). You then confirm the gas produced is carbon dioxide by bubbling it through limewater, which will turn milky

Question 2

Tests for halides

Answer 2

Acidify the sample with nitric acid.
Add silver nitrate solution, AgNO3,
A silver halide precipitate forms if a halide ion is present. The precipitate is indicated by the state symbol (s)

Question 3

Positive result for Bromide ions

Answer 3

cream ppt.

Question 4

Positive result for Chloride ions

Answer 4

white ppt.

Question 5

Positive result for Iodide ions

Answer 5

yellow ppt.

Question 6

Test for SulfATE ions

Answer 6

add a few drops of dilute hydrochloric to the sample.
add a few drops of dilute barium chloride or barium nitrate solution.
a white precipitate. forms if sulfate ions are present. (Insoluble in excess dilute strong acids)

Question 7

Test for SulfITE ions

Answer 7

add a few drops of dilute hydrochloric to the sample.
add a few drops of dilute barium chloride or barium nitrate solution.
a white precipitate. forms if sulfate ions are present. (Soluble in excess dilute strong acids)

Question 9

Test for nitrate ions

Answer 9

Add aqueous NaOH and aluminium foil. Warm gently and test the gas released. The gas given off is ammonia, NH3.
Ammonia is a gas with a characteristic sharp choking smell that turns damp red litmus paper blue.