Write down the reaction involved in preparation of Potassium dichromate from chromine ore.

Open in App

Solution

Following step reactions are involved in preparation of $K_{2} C r_{2} O_{7}$ from Chromite ore ( $F e C r_{2} O_{4}$ )
I. Formation of $N a_{2} C r O_{4}$ (sodium chromate)
$4 F e C r_{2} O_{4} + 16 N a O H + 7 O_{2} \to 8 N a_{2} C r O_{4} + 2 F e_{2} O_{3} + 8 H_{2} O$
II. Conversion of $N a_{2} C r O_{4}$ to $N a_{2} C r_{2} O_{7}$
2 $N a_{2} C r O_{4}$ $+ c o n c . H_{2} S O_{4}$ $\to$ $N a_{2} C r_{2} O_{7}$ + $N a_{2} S O_{4}$ $H_{2} O$
III. Conversion of $N a_{2} C r_{2} O_{7}$ to $K_{2} C r_{2} O_{7}$
$N a_{2} C r_{2} O_{7}$ +2KCl $\to$ $K_{2} C r_{2} O_{7}$ +2 NaCl.
Since the solubility of KCl is less than NaCl, so, $K_{2} C r_{2} O_{7}$ is obtained in form of orange crystals and the former can be removed by filtration.

Suggest Corrections

Similar questions

Describe the preparation of potassium dichromate from iron chromite ore.

What is the effect of increasing pH on a solution of potassium dichromate?

(F e C r_{2} O_{4})

Join BYJU'S Learning Program