identicying non-metal ions

Question 1

how can we test for a carbonate ion?

Answer 1

add dilute acid to the sample

if carbon is present, acid will react with carbonate to make carbon dioxide gas. We will see effervescence(fizzing). This doesn’t prove we have carbon dioxide gas.

Bubble the gas through line water, if the limewater goes cloudy, then this proves that we have carbon dioxide. That means that we started with the carbonate ion.

Question 2

how can we test for halide ions?

Answer 2

add dilute nitric acid to the sample
Add dilute silver nitrate solution. Halide ions produce a precipitate of the silver halide. Each halide makes a different coloured precipitate.

Question 3

what precipitate do chloride ions produce?

Answer 3

white precipitate of silver chloride

Question 4

what precipitate do bromide ions produce?

Answer 4

a cream precipitate of silver bromide

Question 5

what precipitate do iodide ions produce?

Answer 5

a yellow precipitate of silver iodide

Question 6

how can we test for a sulphate ion ?

Answer 6

Add dilute hydrochloric acid to our sample. Add barium chloride solution. If sulphate ions are present we will see a white precipitate