Which of the followng will dissolve in a mixuture of NaOH and `H_(2)O_(2)`?

Options

A. `Fe(OH)_(3)`
B. `Cr(OH)_(3)`
C. `Al(OH)_(3)`
D. `Zn(OH)_(2)`

Answer

To determine which of the compounds will dissolve in a mixture of sodium hydroxide (NaOH) and hydrogen peroxide (H2O2), we need to analyze each option provided. The options are:

1. Fe₂O₃ (Iron(III) oxide)
2. Cr₂O₃ (Chromium(III) oxide)
3. Al(OH)₃ (Aluminum hydroxide)
4. Zn(OH)₂ (Zinc hydroxide)

### Step-by-Step Solution:

**Step 1: Analyze Fe₂O₃**
- Fe₂O₃ can react with NaOH in the presence of H2O2 to form soluble complexes.
- The reaction can be represented as:
\[ \text{Fe}_2\text{O}_3 + 6 \text{NaOH} + 3 \text{H}_2\text{O}_2 \rightarrow 2 \text{Na}_3[\text{Fe(OH)}_6] + 3 \text{H}_2\text{O} \]
- Therefore, Fe₂O₃ will dissolve in the mixture.

**Step 2: Analyze Cr₂O₃**
- Cr₂O₃ is amphoteric and can react with both acids and bases.
- In the presence of NaOH and H2O2, it can also form soluble complexes:
\[ \text{Cr}_2\text{O}_3 + 2 \text{NaOH} + 3 \text{H}_2\text{O}_2 \rightarrow 2 \text{Na}_3[\text{Cr(OH)}_6] + 3 \text{H}_2\text{O} \]
- Thus, Cr₂O₃ will dissolve in the mixture.

**Step 3: Analyze Al(OH)₃**
- Aluminum hydroxide is amphoteric and can dissolve in strong bases.
- The reaction can be represented as:
\[ \text{Al(OH)}_3 + \text{OH}^- \rightarrow \text{[Al(OH)}_4]^- \]
- Therefore, Al(OH)₃ will dissolve in the mixture.

**Step 4: Analyze Zn(OH)₂**
- Zinc hydroxide is also amphoteric and will dissolve in NaOH:
\[ \text{Zn(OH)}_2 + 2 \text{OH}^- \rightarrow \text{[Zn(OH)}_4]^{2-} \]
- Hence, Zn(OH)₂ will dissolve in the mixture.

### Conclusion:
The compounds that will dissolve in a mixture of NaOH and H2O2 are:
- Cr₂O₃
- Al(OH)₃
- Zn(OH)₂

**Final Answer: Cr₂O₃, Al(OH)₃, and Zn(OH)₂ will dissolve in the mixture of NaOH and H2O2.**