Question

An element A in a compound ABD has oxidation number A^n-. It is oxidised by $C{r}_2{O}_7^{-}2$ in acid medium. In the experiment 1.68$\times$${10}^{-}3$ x moles of$K_{2}C{r}_2{O}_7$ were used for 3.26$\times$${10}^{-}3$ moles of ABD. The new oxidation number of A after oxidation is:

• A. 3
• B. 3-n
• C. n-3
• D. +n

Answer 1

The correct option is B

3-n

Equivalent of$C{r}_2{O}_7^{-}2$ = Equivalent ofABD

1.68$\times$${10}^{-}3$$\times$6 =3.26$\times$${10}^{-}3$$\times$X

X =3

New oxidation no =3-n