On reacting with NaOH, which gives inflammable gas?

Options

A. `S`
B. `Zn`
C. `NH_(4)Cl`
D. `I_(2)`

Answer

To determine which element reacts with sodium hydroxide (NaOH) to produce an inflammable gas, we can analyze the reaction step by step.

### Step 1: Identify the Reactants
We are looking for a metal that reacts with sodium hydroxide (NaOH). The common metals that can react with NaOH include zinc (Zn), aluminum (Al), and others.

**Hint**: Think about metals that are known to react with bases.

### Step 2: Understand the Reaction
When certain metals react with sodium hydroxide, they can produce a metal hydroxide and hydrogen gas. The general reaction can be represented as:
\[ \text{Metal} + \text{NaOH} \rightarrow \text{Metal Hydroxide} + \text{Hydrogen Gas} \]

**Hint**: Recall that hydrogen gas is considered inflammable.

### Step 3: Analyze the Specific Reaction
For zinc, the reaction with sodium hydroxide can be written as:
\[ \text{Zn} + 2 \text{NaOH} \rightarrow \text{Na}_2\text{ZnO}_2 + \text{H}_2 \uparrow \]

In this reaction:
- Zinc (Zn) reacts with sodium hydroxide (NaOH).
- Sodium zincate (Na₂ZnO₂) is formed.
- Hydrogen gas (H₂), which is inflammable, is liberated.

**Hint**: Check if the other metals listed in the options also produce hydrogen gas when reacting with NaOH.

### Step 4: Conclusion
From the analysis, we conclude that zinc is the metal that reacts with sodium hydroxide to produce an inflammable gas, which is hydrogen.

**Final Answer**: Zinc (Zn) is the correct answer as it produces inflammable hydrogen gas when reacting with NaOH.

### Summary of Steps
1. Identify the reactants (metals that react with NaOH).
2. Understand the general reaction involving metals and NaOH.
3. Analyze the specific reaction of zinc with NaOH.
4. Conclude that zinc produces hydrogen gas, which is inflammable.