Which of the following statements is TRUE?

a. In general, the solubility of a solid in water decreases with increasing temperature.

b. In general, the solubility of a gas in water decreases with increasing temperature.

c. The solubility of a gas in water usually increases with decreasing pressure.

d. The solubility of an ionic solid in water decreases with increasing temperature.

Answer: Option (b) is the correct answer.

Explanation:

The solubility of a gas is dependent on both pressure and temperature. When we increase the temperature for a gas, then its molecules tend to gain more kinetic energy.

Hence, there occurs more number of collisions between the gas molecules. As a result, intermolecular bonds tend to break down and the molecules of gas become able to escape out of the solution.

Whereas when we increase the pressure on a gas then its molecules come closer to each other. Due to which there will be more number of collisions will take place. Therefore, solubility of a gas increases with increase in pressure.

Thus, we can conclude that the statement in general, the solubility of a gas in water decreases with increasing temperature, is true.

The solubility of a solid increases as the temperature increases.