Question

The value of Henry’s constant $K_H$ ____________.

• A. decreases with increase in temperature.
  
• B. increases with increase in temperature.
  
• C. remains constant.
  
• D. first increases then decreases.

Answer 1

The correct option is B increases with increase in temperature.


Henry’s law

Henry's law states that the amount of gas dissolved in a liquid is proportional to its partial pressure above the liquid. The proportionality constant is called Henry’s constant $K_H$.

$P=K_{H}X$

where,

$P$= Partial pressure of gas

$X$= solubility of gas in liquid

$K_H$ = Henry’s constant

$K_H$ depends on the temperature (T).

As the temperature increases, the kinetic energy of gas particles also increases. Due to increase in the kinetic energy of gas particles, they can easily escape. Thus, solubility of gas in liquid decreases.

Thus, value of Henry’s law constant $K_H$ increases with increase in temperature.

Hence, correct answer is option (A).