Reducing the pressure from 1.0 to 0.5 atm would change the number of molecules in one mole of ammonia to

Options

A. 75% of initial value
B. 50% of initial value
C. 25% of initial value
D. None of these

Explanation

To solve the question "Reducing the pressure from 1.0 to 0.5 atm would change the number of molecules in one mole of ammonia to," we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Moles**:
- One mole of any substance contains a fixed number of molecules, known as Avogadro's number, which is approximately \(6.02 \times 10^{23}\) molecules.

2. **Identify the Given Information**:
- We have 1 mole of ammonia (NH₃).
- The pressure is being reduced from 1.0 atm to 0.5 atm.

3. **Apply the Ideal Gas Law**:
- The ideal gas law states that for a given amount of gas at constant temperature, the number of moles (n) is related to pressure (P) and volume (V) by the equation:
\[ PV = nRT \]
- Here, R is the ideal gas constant and T is the temperature in Kelvin. However, since we are dealing with a fixed amount of gas (1 mole), the number of molecules will remain constant regardless of changes in pressure or volume.

4. **Conclusion**:
- Since we have 1 mole of ammonia, it will always contain \(6.02 \times 10^{23}\) molecules, irrespective of the changes in pressure from 1.0 atm to 0.5 atm. Therefore, the number of molecules does not change.

5. **Final Answer**:
- The number of molecules in one mole of ammonia remains \(6.02 \times 10^{23}\) molecules.