On heating at `750^(@)C`, blue virtiol yields

Options

A. `Cu + SO_(2) + SO_(3)`
B. `Cu_(2)O + SO_(3)`
C. `CuO + SO_(3)`
D. `Cu + S + H_(2)O`

Answer

C

Explanation

Blue virtiol crystals effloresce on expouser and get converted into a pale blue powder, `CuSO_(4)` . `3H_(2)O` . When heated to `100^(@)C`, bluish white monohydrate `CuSO_(4)` . `H_(2)O` is formed. The monohydrate loses last molecule of water at `250^(@)` giving the anhydrous salt `CuSO_(4)`, which is white. These changes are reversible, the colorless anhydrous salt (white) regains its blue color when moistened with a drop of water (test of water due to the formation of blue virtiol, `CuSO_(4)` . `5H_(2)O`). If the anhydrous salt is heated at `750^(@)C`, it decomposes into cuopric oxide and sulphur trioxide:
`CuSO_(4)` `overset (750^(@)C) rarr` `CuO + SO_(3)`