Does the solubility of a substance increase as its temperature increases

Not necessarily

Explanation:

In the event of incresing the temprature it is not necessary that the solubility will increase always. Solubility of solids increases but solubility of gases dectreases on increases the temprature.

In solid solubility may remain unchange on increasing the temprature. This happens due to the fact that on increasing the temprature the mobility of substances increases due to thus the solubility increases.