Question

1000 g solution of 40% solute (by weight) was cooled . 200 g of solute precipitated out . The % concentration remaining solution is:

• A. 25%
• B. 20%
• C. 30%
• D. 35%

Answer 1

The correct option is A 25%

Given,
Total weight of solution $=1000$ $g$
$\%$ of solute $=40\%$
$⟹$ Weight of solute $=\left(\frac{40}{100}\right)\times 1000=400$ $g$
Amount of solute precipitated $=200$ $g$
Amount of solute remaining $=200$ $g$
Weight solvent remaining $=600$ $g$
$\%$ Weight of solute $=$\frac{200}{200+600}\times 100$ =25$\%$