question_answer

In the following reaction                 \[C{{r}_{2}}O_{7}^{-}+14{{H}^{+}}+6{{I}^{-}}\to \,\]\[2C{{r}^{3+}}+3{{H}_{2}}O+3{{I}_{2}}\]                 Which element is reduced           [CPMT 1976]

A)                 \[Cr\]   

B)                 \[H\]

C)                 \[O\]    

D)                 \[I\]

Correct Answer: A

Solution :

           \[\overset{+6\,\,\,\,\,\,\,\,\,\,}{\mathop{C{{r}_{2}}O_{7}^{2-}}}\,+14{{H}^{+}}+6{{I}^{-}}\to \overset{{}}{\mathop{2C{{r}^{3+}}}}\,+3{{H}_{2}}O+3{{I}_{2}}\]