P1 temp change

• What should you be able to describe by the end of the video?

  How to investigate temperature changes
• What type of reaction is being investigated in this practical?

  Exothermic reaction
• What is the neutralization reaction being studied?

  Hydrochloric acid and sodium hydroxide
• What is the independent variable in this experiment?

  Volume of sodium hydroxide solution
• What is the dependent variable in this experiment?

  Maximum temperature reached
• What are the control variables in this experiment?

  Volume and concentrations of acids and bases
• How do you measure the hydrochloric acid for the experiment?

  Using a measuring cylinder for 30 cm³
• Why is the polystyrene cup used in the experiment?

  To reduce heat loss during measurement
• What should be done after adding sodium hydroxide solution?

  Stir the solution gently with a thermometer
• What happens to the temperature during an exothermic reaction?

  The temperature of the solution increases
• What is observed when the thermometer reading stops changing?

  Record the highest temperature reached
• What is the maximum volume of sodium hydroxide solution used in the experiment?

  40 cm³
• What trend is observed as the volume of sodium hydroxide increases?

  Maximum temperature reached increases initially
• Why does the maximum temperature decrease after a certain volume of sodium hydroxide?

  Energy is spread over a larger volume
• What is the purpose of using a lid on the polystyrene cup?

  To reduce heat loss to the air
• What are the steps to conduct the experiment?

  1. Measure 30 cm³ of hydrochloric acid.
  2. Transfer acid to a polystyrene cup.
  3. Measure initial temperature.
  4. Add 5 cm³ of sodium hydroxide solution.
  5. Stir gently and record highest temperature.
  6. Repeat with increasing volumes of sodium hydroxide.
  7. Calculate mean temperature for each volume.
  8. Plot a graph of results.
• What are the implications of using a polystyrene cup in the experiment?

  • Acts as a thermal insulator
  • Reduces heat loss through sides and bottom
  • Minimizes heat loss to the air
• What is the relationship between sodium hydroxide volume and temperature change?

  • Increasing sodium hydroxide volume raises temperature
  • Beyond a certain volume, temperature decreases
  • Energy released is spread over larger volume
• What is the significance of recording two sets of results?

  • Allows calculation of mean temperature
  • Increases reliability of the experiment
  • Helps identify trends in data