Assertion : The difference between `DeltaH and DeltaU` is not significant for systems consisting of only solids and/or liquids.
Reason : Solids and liquids do not suffer any significant volume changes upon heating.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Answer

To analyze the assertion and reason provided in the question, we will break down the concepts step by step.

### Step 1: Understanding the Assertion
The assertion states that "The difference between ΔH and ΔU is not significant for systems consisting of only solids and/or liquids."

- **ΔH (Enthalpy Change)**: This is the heat content of a system at constant pressure.
- **ΔU (Internal Energy Change)**: This is the total energy contained within a system, including kinetic and potential energy of the particles.

For solids and liquids, the volume change upon heating is minimal, which leads us to conclude that the difference between ΔH and ΔU is negligible.

### Step 2: Analyzing the Reason
The reason provided is "Solids and liquids do not suffer any significant volume changes upon heating."

- Solids maintain a fixed volume and shape due to strong intermolecular forces.
- Liquids, while they can change shape, do not significantly change volume when heated because they are confined within a container.

### Step 3: Relating Assertion and Reason
To relate the assertion and reason, we can use the thermodynamic relationship:
\[ \Delta H = \Delta U + P \Delta V \]
Where \( P \Delta V \) is the work done due to volume change.

- For solids and liquids, \( \Delta V \) is approximately zero. Therefore, the equation simplifies to:
\[ \Delta H \approx \Delta U \]
This indicates that the difference between ΔH and ΔU is indeed not significant for solids and liquids.

### Step 4: Conclusion
Both the assertion and reason are true, and the reason correctly explains the assertion. Therefore, the correct interpretation is that both statements are valid and the reason provides a proper justification for the assertion.

### Final Answer
Both the assertion and reason are true, and the reason is the correct explanation of the assertion.

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