11.

K_H  value fro Ar(g), CO₂ (g), HCHO (g) and CH₄  (g) are 40.39 , 1.67, 1.83 x 10^-5  and 0.413 respectively

Arrange these gases in the order of their increasing solubility

a. HCHO< CH₄ < CO₂ < Ar

b. HCHO< CO2 < CH4 < Ar

c.< Ar< CO2 < CH₄ < HCHO

d.Ar< CH₄ < CO₂ < HCHO

Ans. c