`CrO_3` dissolves in aqueous NaOh to give

Options

A. `CrO_4^(2-)`
B. `Cr(OH)_2`
C. `Cr_2O_7^(2-)`
D. `Cr(OH)_3`

Answer

To solve the question of what happens when CrO3 dissolves in aqueous NaOH, we can follow these steps:

### Step 1: Identify the Reactants
We have two reactants:
- CrO3 (chromium trioxide)
- NaOH (sodium hydroxide)

### Step 2: Determine the Nature of Reactants
- CrO3 is acidic in nature.
- NaOH is a strong base.

### Step 3: Write the Reaction
When an acid reacts with a base, they undergo a neutralization reaction. The general form of a neutralization reaction is:
\[ \text{Acid} + \text{Base} \rightarrow \text{Salt} + \text{Water} \]

In this case, the reaction can be written as:
\[ \text{CrO}_3 + \text{NaOH} \rightarrow \text{Na}_2\text{CrO}_4 + \text{H}_2\text{O} \]

### Step 4: Identify the Products
From the reaction, we can identify the products:
- Sodium chromate (Na2CrO4) is the salt formed.
- Water (H2O) is also produced.

### Step 5: Write the Ionic Equation
When Na2CrO4 is formed, it dissociates into its ions in solution:
\[ \text{Na}_2\text{CrO}_4 \rightarrow 2\text{Na}^+ + \text{CrO}_4^{2-} \]

### Conclusion
The final product when CrO3 dissolves in aqueous NaOH is the chromate ion (CrO4^2-).

### Final Answer
CrO3 dissolves in aqueous NaOH to give CrO4^2-.

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