Question

Which of the following is not true regarding Henry's law constant?

• A. It has same unit as that of pressure
• B. It decreases with increase in temperature
• C. It decreases with increase in solubility
• D. Different gas-liquid system have different $K_H$​

Answer 1

The correct option is B It decreases with increase in temperature

Henry's law states that the solubility of a gas in a liquid at a given temperature is directly proportional to its partial pressure of the gas present above the solution.

$P=K_H𝓧$

Where P is the partial pressure​ of gas over the solution, $K_H$ is Henry’s law constant​ and 𝓧 is mole fraction of the​ gas in the solution.

Hence, $K_H$ is the same unit as that of pressure. So, option (a) is correct. $K_H$ increases with increase in temperature, so, option (b) is not correct. Option (c) and option (d) is also correct.

Therefore, the correct answer is option (b).

Theory:
Characteristics of Henry’s Law Constant​:
1. Same unit as that of Pressure​
2. Different gas-liquid system have different values of henry's law constant.​
3. It increases with temperature​
4. It depends on intermolecular forces between gas-liquid.​
5. Its value decreases with increase in solubility .