Question

Solubility of a gas in liquid increases with:
A: increase of pressure and increase of temperature
B: decrease of pressure and increase of temperature
C: increase of pressure and decrease of temperature
D: decrease of pressure and decrease of temperature

Answer 1

This can be explained using Henry's law, in physical chemistry is a gas law, which states that the amount of dissolved gas in liquid is directly proportional to the partial pressure above liquid. This proportionality factor is known as Henry's law constant.

Complete solution:
Henry’s law of solubility can be expressed by the following formula:
${S_g} = k{P_g}$
Here, Sg is solubility of gas, k is the Henry’s constant and Pg is the partial pressure.
Thus, according to Henry's law of solubility, on increasing the pressure of gas above the liquid, concentration of the gas in solution also increases which means solubility of gas in liquid increases with increase of pressure.
Moreover, solubility of a gas in liquid also increases with the lowering of temperature. Actually, increase in temperature increases the kinetic energy as well. The higher kinetic energy leads to more motion/movement in the molecules thereby dissociating the intermolecular bonds and ultimately escaping from the solution. Thus, solubility of gas in liquid decreases with increase of temperature and increases with decrease in temperature.
Hence, Solubility of a gas in liquid increases with increase of pressure and decrease of temperature.

Thus, the correct answer is Option (C).**

Note: Unlikely from the gases, it should be noted that liquids as well as solids depict no change in the solubility with changes in the pressure. However, increase in the temperature increases the solubility of solids in liquids.