Which of the following is false regarding solubility?

a. Gas solubility varies directly with pres-sure.
b. Gas solubility varies directly with temper-ature.
c. Solvents vary in their ability to dissolve substances.
d. The solubility of solids increases with temperature.

ANS: A
The ease with which a solute dissolves in a solvent is its solubility, which is influenced by five factors:
1. Nature of the solute. The ease with which substances go into a solution in a given solvent de-pends on the forces of the solute-solute molecules and varies widely.
2. Nature of the solvent. A solvent's ability to dissolve a solute depends on the bonds of the sol-vent-solvent molecules, and also varies widely.
3. Temperature. Solubility of most solids increases with increased temperature. However, the solubility of gases varies inversely with temperature.
4. Pressure. The solubility of solids and liquids is not greatly affected by pressure. The solubility of gases in liquids, however, varies directly with pressure.
5. Concentration. The concentration of a solute or available solvent will have an effect of how much of the substance goes into solution.