Practical: Investigating Temperature Changes (Edexcel IGCSE Chemistry)

Aim:

• To perform a calorimetry study of the reaction between HCl and NaOH

Apparatus:

• Dilute hydrochloric acid
• Dilute sodium hydroxide solution
• Styrofoam (polystyrene) calorimeter & lid
• 25 cm³ measuring cylinder
• Thermometer & stirrer

Simple calorimeter 

A lid is required to prevent heat loss

Method:

1. Using a measuring cylinder, place 25 cm³ of the NaOH solution into the calorimeter
2. Measure and record the temperature of the solution
3. Add 5 cm³ of the dilute HCl and stir
4. Measure and record the highest temperature reached by the mixture
5. Repeat steps 1 – 4 increasing the amount of acid added by 5 cm³ each time

Results:

• Record your results in a suitable table

Volume of acid (cm3)	Temperature (oC)
5
10
15
20
25

• Plot a graph of the results and draw a line of best fit, using the graph to determine what volume of acid causes the biggest change in temperature

Conclusion:

• The larger the difference in the temperature the more energy is absorbed or released