Solubility The maximum quantity of the substance, expressed in grams, that will dissolve in a certain solvent at a specific temperature. S-C-9-1_Solubility Presentation

Solute + Solvent = Solution Solution – a homogeneous mixture of two or more substances of ions or molecules Solute – the part of a solution that is being dissolved (usually the lesser amount) Solvent – the part of a solution that dissolves the solute (usually the greater amount) Water (Solvent) Salt (Solute) Salt Water (Solution)

Types of Solutions solution that contains the maximum quantity of solute that dissolves at that temperature. Saturated – a solution that contains the maximum quantity of solute that dissolves at that temperature. solution that contains less than the maximum amount of solute that can dissolve at a particular temperature. Unsaturated – a solution that contains less than the maximum amount of solute that can dissolve at a particular temperature. Supersaturated – a solution that contains more solute than a saturated solution. – Supersaturated solutions can be attained by heating the solution up to dissolve more solute at that higher temperature and then letting the solution cool. – Once cooled, agitation causes crystals to precipitate (separate from solution) out of the super saturated solution. S-C-9-1_Solubility Presentation

SATURATED SOLUTION no more solute can dissolve at given temperature UNSATURATED SOLUTION more solute can dissolve SUPERSATURATED SOLUTION becomes unstable, crystals form increasing concentration

Solubility and Temperature Increasing the temperature of a solvent speeds up the particle movement. This causes more solvent particles to bump into the solute, resulting in solute particles breaking loose and dissolving faster. Solubility Curve A graph of the solubility of a compound (grams/100 grams water on the Y-axis) at various temperatures (Celsius on X- axis). Each compound has a different curve. S-C-9-1_Solubility Presentation

Solubility vs. Temperature for Solids Solubility (grams of solute/100 g H 2 O) KI KCl NaNO 3 KNO 3 HClNH 4 Cl NH 3 NaCl KClO 3 SO 2 gases solids Temperature °C Solubility Curve Graph *Solubility is dependent on temperature What trends do you see on the graph? How is the solubility of gases and solids different?

Solubility vs. Temperature for Solids Solubility (grams of solute/100 g H 2 O) KI KCl NaNO 3 KNO 3 HClNH 4 Cl NH 3 NaCl KClO 3 SO 2 gases solids Temperature If you stir faster, will that make you dissolve more? No, it allows you to dissolve substances faster but not more. Increasing the temperature does allow you to dissolve more.

Solubility vs. Temperature What term describes 39g NaCl at 70  C? Saturated! What about 30g at the same temperature? Unsaturated What about 45g at the same temperature? Supersaturated

ToTo Sol. ToTo Solids dissolved in liquid Gases dissolved in liquids As T o solubility Solids are more soluble at...higher temperatures. Gases are more soluble at...lower temperatures & higher pressures.

Pause for Solubility Practice Questions

Solubility of Sodium Acetate Temperature ( o C) Solubility(g/100 g H 2 O) Supersaturated solution Unsaturated solution Saturated