When dil, sulphuric acid reacts with aqueous solution of potassium chromate, the colour changes from yellow to orange. This shows that

Options

A. Chromate ions reduced
B. chromate ions are oxidised
C. monocentric complex is converted into dicentric complex
D. oxygen gets removed from chromate ions

Explanation

To solve the question regarding the color change when dilute sulfuric acid reacts with potassium chromate, we can follow these steps:

### Step 1: Identify the Reactants
The reactants in this reaction are dilute sulfuric acid (H₂SO₄) and potassium chromate (K₂CrO₄).

### Step 2: Understand the Color of Potassium Chromate
Potassium chromate (K₂CrO₄) is known to have a yellow color in its aqueous solution.

### Step 3: Identify the Product Formed
When potassium chromate reacts with dilute sulfuric acid, it forms potassium dichromate (K₂Cr₂O₇) in the presence of acid. Potassium dichromate is known to have an orange color.

### Step 4: Observe the Color Change
The color change observed in the reaction is from yellow (due to K₂CrO₄) to orange (due to K₂Cr₂O₇). This indicates a change in the oxidation state of chromium.

### Step 5: Conclusion About the Reaction
The color change from yellow to orange suggests that potassium chromate (a monomeric complex) is being converted to potassium dichromate (a dimeric complex). This indicates a change in the coordination and oxidation state of chromium.

### Final Answer
The color change from yellow to orange when dilute sulfuric acid reacts with potassium chromate indicates that a monomeric complex (K₂CrO₄) is converted into a dimeric complex (K₂Cr₂O₇).

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