Mixtures Heterogeneous mixtures Homogeneous mixtures Components in different phases Homogeneous mixtures All components in same phase

Solutions Homogeneous mixture Most commonly a solid dissolved in a liquid Gaseous solutions air Solid solutions Alloys

Dissolving process Solute – the component that gets dissolved; the compound in the smaller amount Solvent – the component that does the dissolving; the compound in the larger amount

Dissociation – the process in which a solid dissolves in a liquid Depends on polarity Solvent usually water Polar water molecules are attracted to other polar molecules and to ions Non-polar molecules are attracted to other nonpolar molecules

Caroline Loves Ya’ll  Hydration – water molecules surround the other molecules until the attraction between the water and the ion is stronger than the crystal

Dissociation Individual molecules or ions are pulled away from each other Solvation – the surrounding of the solute particles Once dissociation occurs the ions of the compound act independently

Miscibility Whether or not two liquids will form a solution Miscible liquids are mutually soluble Like dissolves like

Factors that affect solubility Temperature Solids generally more soluble in liquids at higher temperature Gases more soluble in liquids at lower temperatures

Nature of the solvent/solute Pressure Henry’s law – at a given temperature, the solubility of a gas in a liquid is directly proportional to the pressure of the gas above the liquid Nature of the solvent/solute Polarity Molecular size/structure

Factors that affect rate of solution Temperature Agitation Particle Size Surface area Concentration Saturated Unsaturated Supersaturated

Solubility Curves Used to predict the conditions under which substances will form solutions

At 0.0°C, which is more soluble, NaCl or KBr? True or false, temperature has a significant effect on the solubility of NaCl. Which of these dissolutions would have the highest value for heat of solution What would be the approximate value of the heat of solution for NaCl?

At what temperature will 140g of NaClO3 dissolve in 100g of water?

Physical Properties Review Properties that can be measured without changing the substance Intrinsic properties Properties that do not change when the amount of substance changes Density, boiling point, freezing point Extrinsic properties Properties that change with a change in the amount of substance Volume shape size

Dissociation of solute particles Ionic solute particles dissociate in solution and act independently Covalent bonds are not usually broken in solution So covalently bonded molecules will almost always be treated as one particle

Concentration Saturated Unsaturated Supersaturated Contains the normal amount of solute Unsaturated Contains less than the normal amount of the solute Supersaturated Contains more solute than normal