Understand what solubility means it’s definition units and factors :
Definition of solubility
Solubility is defined as the maximum amount of one substance that can be dissolved in another. This is the maximum amount of solute that can be dissolved in an equilibrium solvent , which produces a saturated solution. When certain conditions are met, the additional solute can be dissolved beyond the equilibrium solubility point, which produces a supersaturated solution. Beyond saturation or supersaturation, the addition of more solute does not increase the concentration of the solution.
Instead, the excess solute begins to precipitate out of the solution.
The dissolution process is called dissolution . Solubility is not the same property of matter as the speed of the solution, which describes the speed with which a solute dissolves in a solvent. Solubility is also not the same as the ability of one substance to dissolve another as a result of a chemical reaction. For example, metallic zinc “dissolves” in hydrochloric acid through a displacement reaction which dissolves zinc ions and releases hydrogen gas. Zinc ions are soluble in acid. The reaction does not depend on the solubility of the zinc.
In familiar cases, a solute is a solid (for example, sugar, salt) and a solvent is a liquid (for example, water, chloroform), but the solute or solvent can be a gas, a liquid or solid. The solvent can be a pure substance or a mixture .
The term insoluble implies that a solute is sparingly soluble in a solvent.
In very rare cases, is it true, no solute dissolves. Generally, an insoluble solute still dissolves a little. Although there is no strict limit defining a substance as insoluble, it is common to apply a threshold where a solute is insoluble is less than 0.1 gram dissolved per 100 milliliters of solvent.
Miscibility and solubility
If a substance is soluble in all proportions in a specific solvent, it is called miscible or has the property called miscibility . For example, ethanol and water are completely miscible with each other. On the other hand, oil and water do not mix and do not dissolve into each other. Oil and water are considered immiscible .
Solubility in action
The dissolution of a solute depends on the types of chemical bonds in the solute and the solvent. For example, when ethanol dissolves in water, it retains its molecular identity as ethanol, but new hydrogen bonds are formed between ethanol and water molecules. For this reason, mixing ethanol and water produces a solution with a volume lower than that which you would obtain by adding the starting volumes of ethanol and water.
When sodium chloride (NaCl) or another ionic compound dissolves in water, the compound dissociates into its ions. The ions become solvated or surrounded by a layer of water molecules.
Solubility implies a dynamic equilibrium, involving opposite processes of precipitation and dissolution. Balance is achieved when these processes occur at a constant rate.
Tables and solubility tables indicate the solubility of various compounds, solvents, temperature and other conditions.
IUPAC defines solubility in terms of the proportion of solute relative to the solvent. Allowable concentration units include molarity, molarity, mass per volume, molar ratio, mole fraction, etc.
Factors Affecting Solubility
Solubility can be influenced by the presence of other chemical species in a solution, the phases of the solute and the solvent, the temperature, the pressure, the particle size of the solute and the polarity.