8.5 and Saturation

Solubility: a property of a solute the quantity of solute that can dissolve in a given quantity of solvent. the concentration of a saturated solution of a solute in a solvent at a specific temperature and pressure Solubility in temperature dependent Assume that the solute in not undergoing a chemical reaction with the solvent

Quantitatively, solubility is often expressed as the maximum mass of solute that can be dissolved per 100 g of water at a given temperature

How solubility is represented Many solids have calculated solubility values and can be found in chemicals reference books. E.g. solubility of sodium sulphate in water at 0°C is 4.76 g/100 mL The presence of crystals in a solution is a good indication that it is saturated

A saturated solution A solution that contains the maximum quantity of solute at a given temperature and pressure

Unsaturated solution A solution in which more solute can dissolve at a given temperature and pressure

Supersaturated Solution A solution that contains more than the maximum quantity of solute it should at a given temperature and pressure

Solubility Curves

Solubility Curves These are a graphical representation of the maximum concentration that a solution can take at certain temperatures. Looking at the previous graph… Ex 1. What compound has the highest level of solubility at 20°C? Ex 2. What compound has the lowest solubility at 90°C?

Solubility of Gases! Pop cans, swimming pools, fish tanks, bodies of water are all examples of gases dissolved in water Gases always have higher solubility in water at lower temperatures.... This is the opposite of solids Pressure also affects gases! Higher pressures cause more gas to diffuse in!

Solubility in Water—Generalizations and Examples Solids usually have higher solubility in water at higher temperatures polar liquids in water: solubility usually increases with temperature Non-polar liquids are not soluble in water “immiscible” Elements generally have low solubility in water