`CrO_3` dissolves in aqueous NaOH to give

Options

A. `CrO_4^(2-)`
B. `Cr(OH)_3^(-)`
C. `CrO_7^(2-)`
D. `Cr(OH)_2`

Answer

To solve the question, we need to determine the products formed when chromium trioxide (CrO₃) dissolves in aqueous sodium hydroxide (NaOH). Let's break down the steps involved in this reaction:

### Step 1: Identify the Reactants
The reactants in this reaction are:
- Chromium trioxide (CrO₃)
- Aqueous sodium hydroxide (NaOH)

### Step 2: Write the Reaction
When CrO₃ dissolves in NaOH, it undergoes a chemical reaction. The balanced chemical equation for this reaction is:
\[ CrO_3 + 2NaOH \rightarrow Na_2CrO_4 + H_2O \]

### Step 3: Identify the Products
From the balanced equation, we can identify the products formed:
- Sodium chromate (Na₂CrO₄)
- Water (H₂O)

### Step 4: Write the Ionic Form of the Product
Sodium chromate can also be represented in its ionic form as \( CrO_4^{2-} \) along with the sodium ions \( Na^+ \). Therefore, the product can be expressed as:
\[ Na_2CrO_4 \text{ or } CrO_4^{2-} \]

### Conclusion
Thus, when CrO₃ dissolves in aqueous NaOH, it forms sodium chromate (Na₂CrO₄) and water (H₂O).

### Final Answer
The product formed is \( Na_2CrO_4 \) or \( CrO_4^{2-} \).

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