Question

Evaluate the following statements for their correctness 
A. The elevation in boiling point temperature of water will be same for $01 \,M \,NaCl$ and $01\, M$ urea 
B. Azeotropic mixtures boil without change in their composition
C. Osmosis always takes place from hypertonic to hypotonic solution 
D. The density of $32 \% H _2 SO _4$ solution having molarity $409\, M$ is approximately $126\, g mL ^{-1}$ 
E. A negatively charged sol is obtained when KI solution is added to silver nitrate solution
Choose the correct answer from the options given below :

• A. B and D only
• B. B, D and E only
• C. A and C only
• D. A, B and D only

Hint:

In colligative properties, the presence of ions and solutes plays a significant role in determining changes in properties like boiling point elevation and freezing point depression.

Answer 1

The Correct Option is A

To evaluate and verify the statements given in the question, we'll analyze each one step-by-step to identify their correctness.

1. Statement A: The elevation in boiling point temperature of water will be same for \(0.1 \,M \, \text{NaCl}\) and \(0.1 \,M\) urea.

This statement is incorrect. The elevation in boiling point depends on the van't Hoff factor (\(i\)), which is 2 for NaCl (dissociates into two ions) and 1 for urea (does not dissociate). Therefore, the boiling point elevation will be greater for NaCl than for urea.

1. Statement B: Azeotropic mixtures boil without change in their composition.

This statement is correct. An azeotrope is a mixture of two or more liquids that retains its composition and boiling point during distillation. They exhibit constant boiling behavior, maintaining the same composition in both liquid and vapor phases.

1. Statement C: Osmosis always takes place from hypertonic to hypotonic solution.

This statement is incorrect. Osmosis occurs from a region of lower solute concentration (hypotonic) to higher solute concentration (hypertonic) across a semipermeable membrane until equilibrium is reached.

1. Statement D: The density of a \(32\% \, \text{H}_2\text{SO}_4\) solution having molarity \(409\, M\) is approximately \(126\, \text{g mL}^{-1}\).

This statement is incorrect because the molarity and density values are not realistically compatible. It's likely a misstatement, but it should ideally correlate with theoretical density values.

1. Statement E: A negatively charged sol is obtained when KI solution is added to silver nitrate solution.

This statement is correct. When KI is added to AgNO₃, a negatively charged sol of AgI is formed because the iodide ions impart a negative charge to the sol particles.

After evaluating all the statements, only B and E are true. Thus, the correct answer choice is "B and D only".