Question

Given below are two statements: Statement–I: $K_H$ is constant with change in concentration of gas till the solution is dilute at a given temperature. Statement–II: According to Henry’s law, the partial pressure of gas in vapour phase is inversely proportional to the mole fraction of gas in solution.

• A. Both Statement–I and Statement–II are correct
• B. Both Statement–I and Statement–II are incorrect
• C. Statement–I is correct, Statement–II is incorrect
• D. Statement–I is incorrect and Statement–II is correct

Hint:

Always remember Henry’s law in the form $p = K_H x$. Any mention of \textbf{inverse proportionality} directly signals an incorrect statement.

Answer 1

The Correct Option is C

Concept: Henry’s law relates the solubility of a gas in a liquid to the partial pressure of the gas above the solution at a given temperature: \[ p = K_H x \] where:
$p$ = partial pressure of the gas
$x$ = mole fraction of the gas in solution
$K_H$ = Henry’s law constant Important points:
Henry’s law is valid for dilute solutions
$K_H$ depends only on temperature for a given gas–solvent pair
Step 1: Analyze Statement–I. At a fixed temperature, Henry’s constant $K_H$ does not depend on the concentration of the gas as long as the solution remains dilute. This is consistent with Henry’s law assumptions. \[ \Rightarrow \text{Statement–I is correct} \]
Step 2: Analyze Statement–II. Henry’s law states: \[ p \propto x \] This means the partial pressure of the gas is directly proportional, not inversely proportional, to the mole fraction of the gas in solution. \[ \Rightarrow \text{Statement–II is incorrect} \]
Step 3: Choose the correct option based on analysis. \[ \boxed{\text{Statement–I is correct and Statement–II is incorrect}} \]