Question

Define Henry’s law.

Answer 1

Hint: Henry’s law is a type of gas law that gives a relation between the solubility of gas, pressure, and temperature. The proportionality constant showing the relationship between these factors is known as Henry’s law constant.

Complete step by step answer:
Henry’s law was given by an English chemist named William Henry in the early${19^{th}}$ century.
Henry’s law states that at a constant temperature, the amount of gas particles dissolved in the liquid solution is directly proportional to the gas partial pressure which is above the liquid.
The mathematical formula of Henry’s law is shown below.
$P\alpha C$
$P = {K_H}C$
Where,
*P is the partial pressure of the gas
*C is the concentration of the dissolved gas
*${K_H}$ is Henry’s law constant of the gas
Henry’s law constant can be expressed in mainly two ways depending upon the factors. When Henry’s law constant is expressed in terms of solubility/pressure, then the constant is indicated as Henry’s law solubility constant, this constant is represented as H. When Henry’s law constant is expressed in terms of pressure/solubility then the constant is indicated as Henry’s law volatility constant. This constant is represented by ${K_H}$.
Example of Henry’s law: Henry’s law can be seen in the carbonated drinks. The carbon dioxide present above the bottle is pure and the pressure is higher than the atmospheric pressure. Because of Henry’s law, the solubility of the gas is higher in the unopened bottle. As we open the bottle, the pressurized gas present in the bottle comes in contact with the atmosphere and produces a hissing sound. With the decrease in the partial pressure of the gas above the bottle, the solubility of the gas inside the bottle also decreases because of Henry’s law. This helps the dissolved carbon dioxide gas to come in contact with the surface in the form of small bubbles.


Note:
Different gases show different Henry’s law constant values when dissolved in different solvent as the constant depends on various factors like temperature, nature of gas, and solvent.