Properties of your substance will differ depending on whether your substance is a pure solute or solvent. Having impurities will change the properties of the substance you are studying.

Types of colligative properties:

• vapor pressure lowering: once you dissolve a nonvolatile substance in volatile liquid, the vapor pressure will lower
• boiling point elevation: $\Delta T_b = K_b mi$
  • $K_b$: boiling point elevation constant (found from table)
  • $m$: molality
  • $i$: van’t Hoff factor
• freezing point depression: $\Delta T_f = K_f mi$
  • $K_f$: freezing point depression constant (found from table)
  • $m$: molality
  • $i$: van’t Hoff factor
• osmotic pressure: $\Pi = iMRT$
  • $\Pi$: osmotic pressure
  • $i$: van’t Hoff factor
  • $M$: molarity
  • $R$: gas constant
  • $T$: temperature
• van’t Hoff factor (i): ratio of moles of particles in solution to moles of formula units that are dissolved; # of electrolytes