Solubility Curves

• Solubility curve - usually a curve drawn on a graph of solubility against temperature - shows how solubility changes with temperature - can be used to find mass of crystals formed when solution is cooled.
• • Solubility curves can be used to compare the solubilities of different solutes.
• Four different substances

  
• Can be interpreted from graph:

  • Determine solubility at a specific temperature.
  • Trend in solubility for a given substance (DETAILED).
  • See temperature at which two substances have the same solubility (where two solubility curves cross).
  • Work out the change in solubility between two different temperatures.
• Change between two different temperatures can be used to calculate the mass of crystals that would form when a saturated solution was cooled from a high temperature to a lower temperature:

  1. Use solubility curve to find solubility values for the two different temperatures.
  2. Subtract solubility at lower from higher temperature.
• • Temperature scale can vary but rarely show temperatures below 0°C (water -> solid) or above 100°C (water -> gas).