The product of which of the following reaction is capable of changing orange colour of `Cr_(2)O_(7)^(2-)` to green colour of `Cr^(3+)`.

Options

A. `CH_(2)(COOH)_(2)overset(Delta)rarr`
B. `CH_(3)Cnoverset(H_(3)O^(+))rarr`
C. `HCNoverset(H_(@)O^(+))rarr`
D. `CH_(3)CONH_(2)overset(H_(2)O)rarr`

Answer

c

Explanation

Product of 1,2 and 4 is `CH_(3)COOH`, where as product of 3 is HCOOH which is reducing agent and will be oxidised by `Cr_(2)O_(7)^(2-)`.