A: Solution containing 1 gram equivalent of solute per litre is known as 1N solution
R: N=M `times` n -factor

Answer

To solve the question, we need to analyze both the assertion (A) and the reason (R) provided.

### Step-by-Step Solution:

**Step 1: Understanding the Assertion (A)**
The assertion states that "A solution containing 1 gram equivalent of solute per litre is known as a 1N solution."
- **Explanation**: Normality (N) is defined as the number of gram equivalents of solute per liter of solution. Therefore, if a solution has 1 gram equivalent of solute in 1 liter, it is indeed a 1N solution.

**Step 2: Understanding the Reason (R)**
The reason states that "N = M × n-factor."
- **Explanation**: Here, N represents normality, M represents molarity, and the n-factor is the number of equivalents per mole of solute. This relationship is derived from the definition of normality, where normality can be expressed in terms of molarity multiplied by the n-factor.

**Step 3: Verifying the Truth of Assertion and Reason**
- The assertion is true because it accurately describes what a 1N solution is.
- The reason is also true as it correctly expresses the relationship between normality and molarity, confirming that normality can be calculated using the molarity of the solution and the n-factor.

**Step 4: Establishing the Relationship**
- Since both the assertion and reason are true, and the reason provides a correct explanation for the assertion, we conclude that both are true and the reason is the correct explanation of the assertion.

### Conclusion:
Both the assertion and reason are true, and the reason is the correct explanation of the assertion.

### Final Answer:
Assertion (A) is true, Reason (R) is true, and R is the correct explanation of A.

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