Hydroxide soluble in ammonia is

Options

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

Explanation

To determine which hydroxide is soluble in ammonia, we can follow these steps:

### Step 1: Identify the Hydroxides
First, we need to identify the metal hydroxides that are known to be soluble in ammonia. Common metal hydroxides include those of alkali metals, alkaline earth metals, and transition metals.

### Step 2: Focus on Transition Metals
Among the metal hydroxides, transition metals often form soluble complexes with ammonia. We need to focus on these metals.

### Step 3: Identify Copper Hydroxide
Copper hydroxide (Cu(OH)₂) is a transition metal hydroxide that is known to be soluble in ammonia.

### Step 4: Write the Reaction
When copper hydroxide reacts with ammonia, it forms a soluble complex. The reaction can be represented as follows:
\[ \text{Cu(OH)}_2 + 4 \text{NH}_3 \rightarrow \text{[Cu(NH}_3\text{)}_4]^{2+} + 2 \text{OH}^- \]

### Step 5: Conclusion
Thus, the hydroxide that is soluble in ammonia is copper hydroxide, represented as Cu(OH)₂.

### Final Answer
The hydroxide soluble in ammonia is **Cu(OH)₂**.

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