RP4 - Temperature Changes

• What is the aim of the experiment described?

  Investigate variables affecting temperature change
• 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
• How much hydrochloric acid should be measured for the experiment?

  25 cm​3​ of hydrochloric acid
• Why is the polystyrene cup placed inside a beaker?

  To make it more stable
• What should be done after measuring the temperature of hydrochloric acid?

  Measure 5 cm​3​ of sodium hydroxide
• What is the next step after adding sodium hydroxide to the polystyrene cup?

  Quickly put a lid on the cup
• How should the solution be stirred after adding sodium hydroxide?

  Gently stir with the thermometer through the lid
• When should the temperature be recorded during the experiment?

  When the thermometer reading is constant
• How many times should sodium hydroxide be added to the cup?

  A minimum total of 40 cm​3​ needs to be added
• What should be done to ensure reliability of results?

  Repeat steps 1–7
• What calculation should be performed after the experiment?

  Calculate the mean maximum temperature
• What safety precautions should be taken during the experiment?

  • Wear safety goggles