AS level Chemistry 6 mark help

Two white solids are known to be the compounds magnesium nitrate and barium nitrate. Both solids are soluble in water.
Tests were carried out on the two compounds and the following results were obtained.
Dilute sulfuric acid was added to an aqueous solution of each compound. One showed no change; the other reacted to form a white precipitate.
Dilute sodium hydroxide was added to an aqueous solution of each compound. One showed no change; the other reacted to form a white precipitate.
The solids were heated separately. Both decomposed to form a white residue, a brown gas and a gas which relit a glowing splint. However, one solid decomposed faster than the other.
Discuss how observations from all three tests can be used to identify the two solids.
You should include equations for any reactions that take place (state symbols are not required).

Three tests are used here. Describe the test and the known outcomes for common metal ions. Then use the observed results here, to deduce what the solids are and the reactions that have taken place.

You should have examples of these tests in your notes, especially if you need them for exam questions.