Question

Which of the following reactions do not result in the preparation of potassium dichromate from chromate?

(I) $4FeCr_{2}O_{4} + 8Na_{2}CO_{3} + 7O_{2} \rightarrow$

(II) $Na_{2}CrO_{4} + H_{2}SO_{4} \rightarrow$

(III) $Na_{2}Cr_{2}O_{7} + 2KCl \rightarrow$

• A. (I) and (II)
• B. (II) and (III)
• C. (I) and (III)
• D. (I), (II) and (III)

Answer 1

Answer: (A)

(I) and (II)

Answer 2

(I)

$4FeCr_{2}O_{4} + 8Na_{2}CO_{3} + 7O_{2} \rightarrow 8Na_{2}CrO_{4}$ $$ + 2Fe_{2}O_{3} + 8CO_{2}$$

(II) $2Na_{2}CrO_{4} + H_{2}SO_{4} \rightarrow Na_{2}Cr_{2}O_{7} + Na_{2}SO_{4} + H_{2}O$ (III) $Na_{2}Cr_{2}O_{7} + 2KCl \rightarrow K_{2}Cr_{2}O_{7} + 2NaCl$