Question

NaOH na solushanshma 0.2 mol NaOH ne 22 grams pani ma dissolve kari ne solution banavyu che. Kemli solution ma NaOH no %W/W kayi hase?

• A. 35.71% W/W
• B. 27.78% W/W
• C. 23.38% W/W
• D. 64.86% W/W

Hint:

When calculating weight percentage, ensure that both the weight of the solute and the total solution weight are in grams.

Answer 1

The Correct Option is A

Step 1: Understanding the Problem.
We are asked to calculate the weight percentage (W/W) of NaOH in a solution. The formula for weight percentage is: \[ \text{Weight percentage} = \frac{\text{Weight of solute}}{\text{Weight of solution}} \times 100 \]
Step 2: Calculation.
- Molar mass of NaOH = 40 g/mol.
- Amount of NaOH = \(0.2 \, \text{mol}\). Therefore, the weight of NaOH = \(0.2 \times 40 = 8 \, \text{g}\).
- The weight of water = 22 g.
- The total weight of the solution = \(8 \, \text{g} + 22 \, \text{g} = 30 \, \text{g}\). \[ \text{Weight percentage of NaOH} = \frac{8}{30} \times 100 = 35.71% \]
Step 3: Conclusion.
The correct answer is (A) 35.71% W/W.