Decomposition of ammonium chloride is an endothermic reaction. The equilibrium may be represented as:
`NH_(4)Cl(s) hArr NH_(3)(g)+HCl(g)`
A `6.250 g` sample of `NH_(4)Cl` os placed in an evaculated `4.0 L` container at `27^(@)C`. After equilibrium the total pressure inside the container is `0.820` bar and some solid remains in the container. Answer the followings
If the volume of container were doubled at constant temperature, then what would happen to the amount of solid in the container.

Options

A. Decrease
B. Increases
C. Remain unchanged
D. None

Explanation

To solve the question regarding the effect of doubling the volume of the container on the amount of solid ammonium chloride (NH₄Cl) present, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Reaction**:
The decomposition of ammonium chloride is represented by the equilibrium:
\[ NH_4Cl(s) \rightleftharpoons NH_3(g) + HCl(g) \]
Here, NH₄Cl is a solid, while NH₃ and HCl are gases.

2. **Initial Conditions**:
- A 6.250 g sample of NH₄Cl is placed in a 4.0 L container at 27°C.
- After reaching equilibrium, the total pressure inside the container is 0.820 bar, and some solid NH₄Cl remains.

3. **Effect of Volume Change**:
According to Le Chatelier's principle, if the volume of a container is increased (doubled in this case), the system will respond to counteract the change. This means it will shift in the direction that produces more moles of gas.

4. **Analyzing Moles of Gas**:
In the given reaction:
- On the left side (reactants), we have 1 mole of solid NH₄Cl (which does not contribute to pressure).
- On the right side (products), we have 1 mole of NH₃ and 1 mole of HCl, totaling 2 moles of gas.

5. **Volume Doubling**:
- When the volume is doubled, the concentration of the gaseous products (NH₃ and HCl) decreases because concentration is defined as moles per unit volume.
- As a result, the equilibrium will shift to the right (towards the products) to increase the concentration of gases.

6. **Change in Amount of Solid**:
- Since the equilibrium shifts to the right to produce more gaseous products, the amount of solid NH₄Cl will decrease because it is being converted into NH₃ and HCl.

### Conclusion:
When the volume of the container is doubled at constant temperature, the amount of solid NH₄Cl in the container will **decrease**.

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