Assertion :- Absolute value of enthalpy can not be determined.
Reason :- Enthalpy is defined as H = E + PV, and value of internal energy can not be determined absolutely therefore absolute value of enthalpy can not be determined.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.

Answer

To solve the question regarding the assertion and reason provided, we will break down the concepts of enthalpy and internal energy step by step.

### Step-by-Step Solution:

1. **Understanding Enthalpy**:
- Enthalpy (H) is defined as the total heat content of a system and is given by the equation:
\[ H = E + PV \]
where \(E\) is the internal energy, \(P\) is the pressure, and \(V\) is the volume of the system.

2. **Understanding Internal Energy**:
- Internal energy (E) represents the energy associated with the microscopic components of a system, including their kinetic and potential energies. This includes vibrational, rotational, and translational energies of particles.

3. **Absolute Value of Internal Energy**:
- The absolute value of internal energy cannot be determined because it is a state function that depends on the specific configuration of particles at the microscopic level. We can only measure changes in internal energy (\(\Delta E\)) rather than its absolute value.

4. **Implication for Enthalpy**:
- Since enthalpy is dependent on internal energy, if we cannot determine the absolute value of internal energy, we also cannot determine the absolute value of enthalpy. We can calculate changes in enthalpy (\(\Delta H\)), but not the absolute value of \(H\).

5. **Conclusion**:
- Therefore, the assertion that the absolute value of enthalpy cannot be determined is correct. The reason provided, stating that this is due to the inability to determine the absolute value of internal energy, is also correct and serves as a valid explanation for the assertion.

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