b) ii) Place the remaining residue in a dry test tube. Add 2M nitric acid until all the solid dissolves. Retain the mixture for test (iii) below.

Here are the observations and inferences for the tests on solid M:

b) ii) Place the remaining residue in a dry test tube. Add 2M nitric acid until all the solid dissolves. Retain the mixture for test (iii) below.

Observations	Inferences
The white residue dissolves with effervescence to form a colorless solution.	$\boxed{\text{The residue is a carbonate.}}$