Assertion: Oxides are more ionic than corresponding sulphides.
Reason: Oxygen has higher electron affinity than sulphur.

Options

A. Both A and B true and R is the correct explanation A
B. Both A and R are true but R is not a correct explanation of A
C. A is true but R is false
D. A is false but R is true

Answer

To solve the question, we will analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Oxides are more ionic than corresponding sulphides."
- To evaluate this, we need to consider the nature of ionic compounds. Ionic character in compounds is influenced by the difference in electronegativity between the two elements involved.

2. **Electronegativity Comparison**:
- Oxygen (O) has a higher electronegativity (approximately 3.44 on the Pauling scale) compared to Sulfur (S), which has an electronegativity of about 2.58.
- A higher electronegativity difference between the metal and the non-metal leads to a stronger ionic bond. Since oxygen is more electronegative than sulfur, oxides will generally exhibit more ionic character than corresponding sulphides.

3. **Conclusion on Assertion**:
- Therefore, the assertion that "Oxides are more ionic than corresponding sulphides" is **True**.

4. **Understanding the Reason**:
- The reason states that "Oxygen has higher electron affinity than sulphur."
- Electron affinity is the energy change when an electron is added to a neutral atom.

5. **Electron Affinity Comparison**:
- In fact, the electron affinity of sulfur is greater than that of oxygen. This is due to the smaller size of oxygen, which leads to increased inter-electronic repulsion when an additional electron is added.
- Thus, the statement that "Oxygen has higher electron affinity than sulphur" is **False**.

6. **Final Evaluation**:
- Since the assertion is true and the reason is false, we conclude that the correct answer is that the assertion is true while the reason is false.

### Final Answer:
- **Assertion**: True
- **Reason**: False
- **Correct Option**: C (Assertion is true, Reason is false)