When 25 g of `Na_(2)SO_(4)` is dissolved in `10^(3)` Kg of solution, its concentration will be

Options

A. ` 2.5 ` ppm
B. `25 ` ppm
C. ` 250 ` ppm
D. `100` ppm

Explanation

To find the concentration of Na₂SO₄ in ppm when 25 g is dissolved in 10³ kg of solution, we can follow these steps:

### Step 1: Convert mass of Na₂SO₄ to kilograms
Given:
- Mass of Na₂SO₄ = 25 g

To convert grams to kilograms:
\[ \text{Mass in kg} = \frac{\text{Mass in g}}{1000} = \frac{25}{1000} = 0.025 \text{ kg} \]

### Step 2: Identify the total mass of the solution
Given:
- Total mass of the solution = 10³ kg = 1000 kg

### Step 3: Use the formula for ppm
The formula for concentration in ppm (parts per million) is:
\[ \text{ppm} = \left( \frac{\text{mass of solute (kg)}}{\text{total mass of solution (kg)}} \right) \times 10^6 \]

### Step 4: Substitute the values into the formula
Substituting the values we have:
\[ \text{ppm} = \left( \frac{0.025 \text{ kg}}{1000 \text{ kg}} \right) \times 10^6 \]

### Step 5: Calculate the ppm
Calculating the above expression:
\[ \text{ppm} = \left( \frac{0.025}{1000} \right) \times 10^6 = 0.000025 \times 10^6 = 25 \text{ ppm} \]

### Conclusion
The concentration of Na₂SO₄ in the solution is **25 ppm**.

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