Dissolving Process Polarity The polarity of the solute and solvent has a great impact on whether they will dissolve Like dissolves like (polar dissolves polar) Miscible – two or more liquids that are able to dissolve into each other in various proportions. Immiscible – two or more liquids that do not mix with each other.

How to dissolve immiscible liquids A compound that concentrates at the boundary surface between two immiscible phases. It has a polar end and a nonpolar end. Example is a Any mixture of two or more immiscible liquids in which one liquid is dispensed in the other. Surfactant detergent Emulsion

Dissolving Process Surface area Larger the surface area, the faster the solute will dissolve (lots of small pieces will dissolve faster than 1 big piece) Agitation (stirring) increases the rate of dissolving Temperature Temperature affects solubility For solids and liquids, increase temperature = increase in solubility When gases are involved, an increase in temperature = decrease in solubility.

Saturation A solution that cannot dissolve any more solute under the current conditions. A solution that contains less solute than a saturated solution and is able to dissolve additional solute. A solution that contains more solute than what is required to reach equilibrium at a given temperature Saturated solution Unsaturated solution Supersaturated solution

Unsaturated verses Saturated

Solubility Graph How many grams of NH4Cl can be dissolved in 400 grams of water at 70 ̊C? 60x4 = 240 At 50 ̊C, 120 g of NaNO3 is dissolved in 100 g of water. Is this solution saturated, supersaturated or unsaturated? Graph says 111, 120 is more so supersaturated How much precipitate will form when a saturated solution of RbCl is cooled from 85 ̊C to 5 ̊C? 130-80=50 g

Henry’s Law Brownian Motion The law that states that at constant temperature, the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas on the surface of the liquid. In other words, the higher the pressure of the gas, the higher its solubility. Brownian Motion The random movement of microscopic particles suspended in a fluid.

Another Effect of Solubility Colligative properties

What is a colligative property? A property of a substance or system that is determined by the number of particles present in the system but independent of the particles themselves. In other words, it doesn’t matter what it is but how much there is. Examples: Freezing point depression – lowering of the freezing point of a solution (salt on roads in winter) Boiling point elevation – raising of the boiling point of a solution.

Homework Solubility Graph Worksheet