When potassium dichromate is heated with potassium hydroxide and the solution obtained is acidified, the colour becomes

Options

A. yellow
B. green
C. orange
D. blue

Explanation

To solve the question regarding the color change when potassium dichromate is heated with potassium hydroxide and then acidified, we can follow these steps:

### Step 1: Identify the Initial Reactants
The initial reactants are potassium dichromate (K2Cr2O7) and potassium hydroxide (KOH). Potassium dichromate is known for its orange color.

### Step 2: Reaction of Potassium Dichromate with Potassium Hydroxide
When potassium dichromate is heated with potassium hydroxide, it undergoes a reaction to form potassium chromate (K2CrO4), which is yellow in color. The reaction can be represented as:
\[ K_2Cr_2O_7 + 2KOH \rightarrow 2K_2CrO_4 + H_2O \]

### Step 3: Acidification of the Product
After forming potassium chromate, the next step is to acidify the solution. Acidifying potassium chromate (K2CrO4) with sulfuric acid (H2SO4) will convert it back to potassium dichromate (K2Cr2O7), which is orange in color. The balanced reaction for this step is:
\[ 2K_2CrO_4 + H_2SO_4 \rightarrow K_2Cr_2O_7 + K_2SO_4 + H_2O \]

### Step 4: Determine the Final Color
The final product after acidification is potassium dichromate (K2Cr2O7), which has an orange color. Therefore, the color of the solution after acidification will be orange.

### Final Answer
The color becomes **orange**.

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