When we add salt to a glass of water, depending on the amount placed in this glass, the salt will dissolve or not.
The same is true when we put too much sugar in black coffee. Not all sugar will dissolve in coffee. The amount that does not dissolve will be deposited in the fund.
O solubility coefficient is the amount of a substance required to saturate a standard amount of solvent at a given temperature and pressure.
In other words, solubility is defined as the concentration of a substance in solution that is in equilibrium with the pure solute at a given temperature.
AgNO3 - 330g / 100mL of H2O at 25 ° C
NaCl - 357g / l H2O at 0 ° C
AgCl - 0.00035g / 100mL of H2O at 25 ° C
See that AgCl is very insoluble. When the solubility coefficient is almost nil, the substance is insoluble in that solvent.
When two liquids do not mix, we call them immiscible liquids (water and oil, for example).
When two liquids mix in any proportion, that is, the solubility coefficient is infinite, the liquids are miscible (water and alcohol, for example).