If 100 ml hydrogen chloride is completely decomposed the volume of `H_(2)` formed will be (P and T are constant).

Options

A. 20 ml
B. 200 ml
C. 100 ml
D. 50 ml

Explanation

To solve the problem of how much hydrogen gas (H₂) is formed from the complete decomposition of 100 ml of hydrogen chloride (HCl), we can follow these steps:

### Step 1: Write the balanced chemical equation
The decomposition of hydrogen chloride can be represented by the following balanced equation:
\[ 2 \text{HCl} \rightarrow \text{H}_2 + \text{Cl}_2 \]

### Step 2: Determine the stoichiometry of the reaction
From the balanced equation, we see that:
- 2 moles of HCl produce 1 mole of H₂ and 1 mole of Cl₂.

### Step 3: Relate volume to moles
Since the reaction occurs at constant pressure and temperature, the volume of gas produced is directly proportional to the number of moles of gas. Therefore, we can use the volume of HCl to find the volume of H₂ produced.

### Step 4: Calculate the volume of H₂ produced
Given that 100 ml of HCl is decomposed:
- From the stoichiometry, 2 volumes of HCl produce 1 volume of H₂.
- Therefore, if 100 ml of HCl decomposes, the volume of H₂ produced can be calculated as follows:
\[ \text{Volume of H₂} = \frac{1}{2} \times \text{Volume of HCl} \]
\[ \text{Volume of H₂} = \frac{1}{2} \times 100 \, \text{ml} = 50 \, \text{ml} \]

### Conclusion
Thus, the volume of hydrogen gas (H₂) formed from the complete decomposition of 100 ml of hydrogen chloride (HCl) is **50 ml**.

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