Question

name the substance which remains in test tube heating ferrous sulfate

Answer 1

the answer is Fe2O3, that is ferric oxide which is reddish brown in colour remain in a test tube after heating ferrous sulphate.

Answer 2

2FeSO4(s)..heat.......) Fe2O3(s)+ SO2(g)+So3(g)
so the substance that remains in test tube is ferric oxide.