A: 1 gram of salt in `1 m^(3)` of solution has concentration of 1 ppm.
R: ppm is defined as number of parts by mass of solute per million parts of solution.

Options

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

Answer

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

**Assertion (A):** 1 gram of salt in 1 m³ of solution has a concentration of 1 ppm.
**Reason (R):** ppm is defined as the number of parts by mass of solute per million parts of solution.

### Step-by-Step Solution:

1. **Understanding ppm:**
- ppm stands for "parts per million." It is a way to express very dilute concentrations of substances. It indicates how many parts of a substance (solute) are present in one million parts of the solution.

2. **Converting Units:**
- We have 1 m³ of solution. We know that:
- 1 m³ = 1,000 liters (L)
- 1 liter = 1,000 milliliters (mL)
- Therefore, 1 m³ = 1,000,000 mL (10^6 mL).

3. **Calculating Concentration in ppm:**
- The formula for calculating ppm is:
\[ \text{ppm} = \left( \frac{\text{mass of solute (g)}}{\text{volume of solution (mL)}} \right) \times 10^6 \]
- Here, the mass of solute (salt) = 1 gram, and the volume of solution = 1,000,000 mL.
- Plugging in the values:
\[ \text{ppm} = \left( \frac{1 \text{ g}}{10^6 \text{ mL}} \right) \times 10^6 = 1 \text{ ppm} \]

4. **Evaluating the Assertion:**
- The assertion states that 1 gram of salt in 1 m³ of solution has a concentration of 1 ppm. From our calculation, this is indeed correct.

5. **Evaluating the Reason:**
- The reason states that ppm is defined as the number of parts by mass of solute per million parts of solution. This is also a correct definition of ppm.

6. **Conclusion:**
- Both the assertion and the reason are true, and the reason correctly explains the assertion. Thus, the correct answer is that both assertion and reason are true, and the reason is the correct explanation of the assertion.

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

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