Assertion : Compressibility factor of ideal gases is one.
Reason : For ideal gases `pV=nRT` equation is obeyed.

Options

A. Assertion and reason both are correct statements and reason is correct explanation for assertion.
B. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C. Assertion is correct statement but reason is wrong statement.
D. Assertion is wrong statement but reason is correct statement.

Answer

To solve the question regarding the assertion and reason about the compressibility factor of ideal gases, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that the compressibility factor (Z) of ideal gases is one.
- The compressibility factor is defined as \( Z = \frac{pV}{nRT} \), where \( p \) is the pressure, \( V \) is the volume, \( n \) is the number of moles, \( R \) is the universal gas constant, and \( T \) is the temperature.

2. **Analyzing the Ideal Gas Equation**:
- The ideal gas law is given by the equation \( pV = nRT \).
- This equation holds true for ideal gases under ideal conditions (high temperature and low pressure).

3. **Substituting in the Compressibility Factor Formula**:
- If we substitute \( pV \) from the ideal gas equation into the compressibility factor formula:
\[ Z = \frac{pV}{nRT} = \frac{nRT}{nRT} = 1 \]
- This shows that for ideal gases, the compressibility factor \( Z \) is indeed equal to 1.

4. **Understanding the Reason**:
- The reason states that the equation \( pV = nRT \) is obeyed for ideal gases.
- Since the ideal gas law is the basis for defining the compressibility factor, this reason supports the assertion.

5. **Conclusion**:
- Both the assertion and the reason are true.
- The reason correctly explains why the assertion is true.

### Final Answer:
- **Assertion**: True
- **Reason**: True
- **Explanation**: The reason is a correct explanation for the assertion.