Question

Consider the following reactions: \[ K_2Cr_2O_7 + 2 KOH \xrightarrow{ \text{heat} } [A] \] \[ [A] + H_2SO_4 \xrightarrow{} [B] + K_2SO_4 \] The products [A] and [B], respectively are:

• A. \( K_2Cr(OH)_6 \) and \( Cr_2O_3 \)
• B. \( K_2CrO_4 \) and \( Cr_2O_3 \)
• C. \( K_2CrO_4 \) and \( K_2Cr_2O_7 \)
• D. \( K_2CrO_4 \) and \( CrO \)

Hint:

When potassium chromate reacts with sulfuric acid, it produces chromium trioxide. The reaction typically forms an orange solution due to the presence of \( K_2Cr_2O_7 \).

Answer 1

The Correct Option is C

The first reaction shows the reaction of \( K_2Cr_2O_7 \) (potassium dichromate) with KOH (potassium hydroxide) under heat. The product formed is potassium chromate \( K_2CrO_4 \), which is the compound [A].
- In the second reaction, \( K_2CrO_4 \) reacts with sulfuric acid (H2SO4), resulting in chromium trioxide \( Cr_2O_3 \) as the product [B]. Thus, the correct products are [A] = \( K_2CrO_4 \) and [B] = \( K_2Cr_2O_7 \).