Solutions Question 230

Question: A solute X has a solubility of 10.0 g in 100 g of water at $ 25{}^\circ C. $ If a solution containing 4.0 g of solute in 50 g of water is subjected to evaporation at constant temperature of $ 25{}^\circ C $ , the osmotic pressure of the solution

Options:

A) remains unchanged throughout

B) increases continuously

C) increases to constant value

D) decreases to constant value

Show Answer

Answer:

Correct Answer: C

Solution:

The given solution is unsaturated (saturated one contains 5 g of solute in 50 g of water). On evaporation, concentration of solution increases to saturation and thereafter becomes constant due to excess solid separating out. Hence, osmotic pressure first increases and then becomes constant.