Question

With an increase in temperature :
a.) Solubility of solids in liquids generally decreases
b.) Solubility of solids is unaffected
c.) Solubility of solids in liquids generally increases
d.) Solubility of gases in liquids decreases

Answer 1

Hint: We know that in solids, the molecules are compactly packed and negligible intermolecular space. However, in liquids; the intermolecular space increases with decrease in intermolecular forces and further the gases molecules are at very large distances. With an increase in temperature, the kinetic energy of the molecules increases resulting in an increase in motion of the molecules. Some types of molecules that require motion dissolve well while the ones that already have sufficient energy do not dissolve.

Complete answer:
We all know that the solids have the highest degree of intermolecular forces and then the liquids and at last the gases. The second point to remember is that due to strong intermolecular forces, the solid molecules are strongly bonded and then liquids which have some intermolecular space between two molecules and the gases are far apart.
We know that with an increase in temperature, the kinetic energy of the molecules increases. So, with an increase in kinetic energy, the solvent molecules can more effectively break the solids that are present in the solvent. So, the molecules of the solid will be more dissolved in the solvent. This means, with an increase in temperature, the solubility of solids in liquids increases.
Thus, the option c.) may be the correct answer.
If we talk about gas, the increase in temperature will result in an increase in kinetic energy. As a result, the gas molecules also absorb energy and move with more speed. So, their kinetic energy also increases. As a result, there is more motion in gas molecules and thus, the intermolecular bonds may break resulting in the escape of gases from the solution. So, with an increase in temperature, the solubility of gases decreases in the liquids.
Thus, the option d.) may also be the correct answer.

So, the correct answer is the option c.) and d.).

Note: It must be noted that the intermolecular forces are inversely proportional to intermolecular spaces. If the intermolecular force of attraction is high, the intermolecular space would be less which is in case of solids. With an increase in temperature, the molecules gain energy and thus, their kinetic energy increases. The solid molecules by gaining energy start vibrating resulting in overcoming intermolecular forces of attraction.