All hydroxides are insoluble except those of sodium, potassium,
ammonium, calcium, barium, and strontium.Some general trends of solubility are shown in the chart below.
(^) Temperature Effect^ Pressure Effect
Solid
Solubility usually increases with
temperature increase.
Little effect
Gas
Solubility usually decreases with
temperature increase.
Solubility varies in direct proportion to the pressure applied
to it: Henry’s Law.
Factors That Affect Rate of Solution Making (How Fast They
Go Into Solution)
The following procedures increase the rate of solution making.Pulverizing
increases surface exposed to solvent.Stirring
brings more solvent that is unsaturated into contact with solute.Heating
increases molecular action and gives rise to mixing by convection currents. (This
heating affects the solubility as well as the rate of solubility.)Summary of Types of Solutes and Relationships of Type to
Solubility
Generally speaking, solutes are most likely to dissolve in solvents with similar
characteristics; that is, ionic and polar solutes dissolve in polar solvents, and
nonpolar solutes dissolve in nonpolar solvents.
It should also be mentioned that polar molecules that do not ionize in
aqueous solution (e.g., sugar, alcohol, glycerol) have molecules as solute
particles; polar molecules that partially ionize in aqueous solution (e.g., ammonia,
acetic acid) have a mixture of molecules and ions as solute particles; and polar
molecules that completely ionize in aqueous solution (e.g., hydrogen chloride,
hydrogen iodide) have ions as solute particles.