Question

Potassium iodide reacts with acidified $K_{2}C{r}_2{O}_7.$ Number of moles of $KI$ required for one mole of $K_{2}C{r}_2{O}_7$ is _____.

Answer 1

Answer: 6

$[C{r}_2{O}_7^{2-}+14H^{+}+6e^{-}\to 2C{r}^{3+}+7H_{2}O]$

$[2I^{-}\to I_2+2e^{-}]\times 3$

$C{r}_2{O}_7^{2-}+14H^{+}+6I^{-}\to 2C{r}^{3+}+7H_{2}O+3I_2$

$1$ mole of $K_{2}C{r}_2{O}_7$ reacts with $6$ moles of $KI$.