Question

Assertion (A): Elevation in boiling point is a colligative property.
Reason (R): Elevation in boiling point is directly proportional to molality.

• A. Both $A$ and $R$ are true and $R$ is the correct explanation of $A$
• B. Both $A$ and $R$ are true but $R$ is NOT the correct explanation of $A$
• C. $A$ is true but $R$ is false
• D. $A$ is false and $R$ is true

Answer 1

The correct option is A Both $A$ and $R$ are true and $R$ is the correct explanation of $A$

Elevation in boiling point is a colligative property. It depends on the amount of solute present in the solution. So it is directly proportional to molality also.
$\Delta T_b=K_b\times m$
Where, $\Delta T_b=\text{Elevation in boiling point}$
$m=\text{molality}$