Temperature change

• What is the aim of the experiment described in the study material?


  To investigate the variables that affect temperature change in chemical reactions
• What equipment is needed for the temperature change experiment?

  • 2 M hydrochloric acid
  • 2 M sodium hydroxide solution
  • Expanded polystyrene cups and lids with thermometer holes
  • Thermometers
• Why is a polystyrene cup used in the experiment?


  To provide stability and insulation for temperature measurement
• How much hydrochloric acid should be measured for the experiment?


  25 cm³
• What should be done after measuring the hydrochloric acid?


  Place the cup inside a beaker for stability
• What is the first step after placing the cup in the beaker?

  Measure and record the temperature of the hydrochloric acid
• How much sodium hydroxide should be added to the hydrochloric acid initially?


  5 cm³
• What should be done after adding sodium hydroxide to the cup?


  Quickly put a lid on the cup and gently stir the solution
• How should the thermometer be used during the experiment?


  Through the hole in the lid to stir the solution
• When should the temperature be recorded during the experiment?

  When the reading on the thermometer stops changing and becomes fairly constant
• How many times should sodium hydroxide be added to the cup?


  A minimum total of 40 cm³ needs to be added
• Why is it important to repeat steps 1–7 in the experiment?

  To ensure reliability of results
• What should be calculated after completing the experiment?

  The mean maximum temperature reached for each of the sodium hydroxide volumes
• What safety precautions should be taken during the experiment?


  • Wear safety goggles