Heterogeneous Mixture: Does not have a definite composition, non-uniform
Homogeneous Mixture: Uniform throughout
Ways to separate mixtures:
- Filtration
- Distillation
- Evaporation
- Chromatography
- Crystallization
- Solutions are Homogeneous Mixtures
- The concentration of a solution may be expressed as: molarity, percent by volume, percent by mass, or parts per million- Table T
- An increase in temperature, stirring, and surface area increases the rate of dissolving
- Polars dissolve in polar solvents
- Non-polars dissolve in non-polar solvents
- Solids dissolve best at high temperatures
- Gases dissolve best at high pressure and low temperatures
- Solutions have lower freezing points and higher boiling points than pure substances
- Ionic compounds form ions in solution and are electrolytes -conducts electricity when dissolved in water
- Use Table F to determine if a compound is soluble
Predict solubility at different temperatures
How much more solute can you add if the temperature changes
How much solute will precipitate out if the temperature changes
Saturated solution- a solution in which the maximum amount of solute has dissolved in the solvent at a given temperature
Unsaturated solution- a solution in which the solute has completely dissolved in the solvent
Supersaturated solution- a solution in which the amount of solute dissolved under given conditions exceeds its supposed upper limit
Properties of Matter
Physical Properties: Can be observed without changing identity (Density, color, conductivity)
Chemical Properties: Can be observed when matter is reacting (Flammability, heat of combustion)
Physical Change: Formula does not change (Boiling, melting, dissolving)
Chemical Change: Reaction occurs, new products (Rusting, burning)
A pure substance, such as an element, has a constant composition and has constant properties throughout a given sample and from sample to sample.
Elements cannot be broken down by chemical change.
