Assertion: The chemical potential of pure water at normal temperature and pressure is zero.
Reason: In solution, value of water potential is always positive.

Options

A. If both Assertion and Reason are true and Reason is 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 and false.

Answer

To solve the assertion and reason question, we can break it down into the following steps:

### Step 1: Analyze the Assertion
The assertion states that "The chemical potential of pure water at normal temperature and pressure is zero."

- **Explanation**: In thermodynamics, the chemical potential of a substance is a measure of its potential to undergo a change. For pure substances, especially under standard conditions (normal temperature and pressure), the chemical potential is defined to be zero. This is a convention used in thermodynamics to simplify calculations and comparisons.

### Step 2: Analyze the Reason
The reason states that "In solution, the value of water potential is always positive."

- **Explanation**: Water potential (Ψ) is a measure of the potential energy of water in a system. It is affected by solute potential (Ψs) and pressure potential (Ψp). When solutes are added to pure water, the solute potential becomes negative (as solutes lower the potential energy of water), thus making the overall water potential (Ψ) less than zero. Therefore, the statement that water potential is always positive in solution is incorrect.

### Step 3: Determine the Truth Values
- **Assertion**: True (the chemical potential of pure water at normal conditions is zero).
- **Reason**: False (the value of water potential in solution can be negative, especially when solutes are present).

### Step 4: Conclusion
Since the assertion is true and the reason is false, the correct answer to the question is that the assertion is true, and the reason is false.

### Final Answer
The correct option is that the assertion is true and the reason is false.

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