Sulphur dioxide can't act as a`//`an

Options

A. dehydrating agent
B. oxidizing agent
C. reducing agent
D. bleaching agent

Answer

1

Explanation

Since `S` atom in `SO_(2)` is in the intermediate oxidation state `(+4)`,thus,it may act both as an oxidizing as well as a reducing agent.
Sulphur dioxide is one of the few common gases that is a reducing agent ,itself being easily oxidized to the sulphate ion.
`SO_(2)(aq.)+2H_(2)O(l)rarrSO_(4)^(2-)(aq.)+4H^(+)(aq.)+2e^(-)`
Thus, the aqueous solution of `SO_(2)` acts as a reducing agent as sulphurous acid change into sulphuric acid giving nascent hydrogen:
`SO_(2)+H_(2)OrarrH_(2)SO_(3)`
`H_(2)SO_(3)+H_(2)OrarrH_(2)SO_(4)+2H`
It also acts as an oxidizing agent particularly when treated with stonger reducing agent .`SO_(2)` in presence of moisture acts as a bleaching agent by reducing the chromophoric group (group that gives rise to colours)of a coloured substances. However,it can't play the role of a dehydrating agent.