Question

The molar solubilities of helium, nitrogen, and oxygen are plotted against the partial pressure of the gases at a constant temperature.
Henry’s law constant for these gases will lie in the following sequence:

• A. $O_2>N_2>He$
• B. $O_2<N_2<He$
• C. $O_2=N_2=He$
• D. $O_2>N_2<He$

Answer 1

The correct option is B $O_2<N_2<He$

According to Henry's law mole fraction of gas in the solution is proportional to the partial pressure of the gas over the solution.Given by
$P=K_{H}X$ where each term has its usual meaning
When we draw a horizontal line on the graph which represent constant mole fraction or solubility we get
$P_{He}>P_{N_2}>P_{O_2}$
$\therefore (K_H{)}_{He}>(K_H)N_2>(K_H{)}_{O_2}$