Question

If 1 mole of Potassium Chloride weighs 0.07456 kg, approximately how many moles of Potassium Chloride can be dissolved in 100 litres of water at 36°C?

• A. 700
• B. 650
• C. 480
• D. 540

Hint:

For moles = mass / molar mass, ensure consistent units — both in kg or grams before calculation.

Answer 1

The Correct Option is A

From the graph, the solubility of Potassium Chloride (■) at 36°C is approximately 0.52 kg/L. Amount dissolved in 100 L: \[ 0.52 \ \text{kg/L} \times 100 \ \text{L} = 52 \ \text{kg} \] Given that 1 mole of KCl weighs 0.07456 kg, the number of moles is: \[ \frac{52}{0.07456} \approx 697.86 \ \text{moles} \] Rounding to the nearest whole number gives 700 moles.