The gas that is liberated when iron is heated with concentrated tetraoxosulphate (VI)acid is?

A. H2S
B. SO2

C. HCI
D. SO3
E. O2

Correct Answer:

Option B – SO2

Explanation

2Fe (s) + 6H2SO4 (l) → Fe2(SO4)3 (aq) + 3SO2 (g) + 6H2O (l)