reactions

• saturated solution

  solution with maximum amount of solute dissolved in a solvent at a specific temperature
• purity of a substance

  if substance is impure melting point decreases and boiling point increases

  and melt and boil over a range of temperatures
• separation methods to obtain pure substance (filtration, evaporation, crystallization)

  1. filtration : insoluble solid in a liquid, can be separated using a filter paper (insoluble solid is residue which is left on filter paper and water is filtrate)
  2. crystallization : solution contains soluble substance, heat solution to evaporate some water and make it saturated, leave solution to cool, and you will see some crystals forming, filter them, wash and dry.
  3. evaporation: keep heating solution till all water is gone/evaporated, the undissolved solid will appear, keep heating till dry.
• separation methods

  1. separating two solids: dissolve in solute which dissolves at least one of the solid, filter mixture to obtain undissolved solid, for the dissolved solid; evaporate and dry. (for sugar and salt solution use ethanol as solvent)
  2. simple distillation : to obtain solvent from a solution, heat solution, water vapor rises into condenser leaving undissolved solid behind, the condenser is cold so water vapor condenses to water, and water drips into beaker giving us a distilled "product name"