Required practicals

• Exothermic reaction


  Reaction that releases energy
• Endothermic reaction


  Reaction that absorbs energy
• Investigating temperature changes in an exothermic reaction

  1. Measure volume of hydrochloric acid

  2. Transfer acid to polystyrene cup

  3. Measure initial temperature

  4. Add sodium hydroxide solution

  5. Fit lid and insert thermometer

  6. Stir solution

  7. Record maximum temperature reached

  8. Repeat with increasing volumes of sodium hydroxide
• Independent variable


  • Volume of sodium hydroxide solution
• Dependent variable


  • Maximum temperature reached
• Control variables


  • Volume of hydrochloric acid
  • Concentrations of hydrochloric acid and sodium hydroxide
• Increasing volume of sodium hydroxide

  Increases maximum temperature reached
• Increasing volume of sodium hydroxide beyond a certain point

  Decreases maximum temperature reached
• Reason for using polystyrene cup with lid: