Core Practical 6 Edexcel Chemistry: Investigating Rate Of Reaction

Core Practical 6 in Edexcel A Level Chemistry involves investigating how temperature affects the rate of reaction. This practical focus on collecting reliable data to determine the effect of temperature changes on reaction rates is a key part of understanding collision theory and reaction kinetics.

Objective

The objective of Core Practical 6 is to measure how temperature changes influence the time taken for a reaction to complete. The experiment often uses sodium thiosulfate and hydrochloric acid, as their reaction produces a precipitate of sulphur, turning the solution cloudy.

Apparatus And Materials

• Sodium thiosulfate solution
• Hydrochloric acid
• Conical flask
• Measuring cylinders
• Stopwatch
• Bunsen burner or water bath
• Thermometer
• Heatproof mat
• A piece of paper with a marked cross

Method

1. Prepare the reaction mixture:
   • Measure a fixed volume of sodium thiosulphate solution using a measuring cylinder and pour it into a conical flask.
   • Place the conical flask on a piece of paper with a visible cross marked on it.
2. Adjust the temperature:
   • Heat the sodium thiosulphate solution to a desired temperature using a water bath or Bunsen burner.
   • Use a thermometer to check the solution’s temperature.
3. Start the reaction:
   • Add a measured volume of hydrochloric acid to the conical flask and quickly swirl to mix the reactants.
   • Start the stopwatch immediately.
4. Observe the reaction:
   • Look through the solution at the marked cross. Stop the stopwatch when the cross is no longer visible due to the formation of sulphur precipitate.
5. Repeat for different temperatures:
   • Repeat the experiment for a range of temperatures (e.g., 20°C, 30°C, 40°C, 50°C).
   • Record the time taken for the cross to disappear for each temperature.
6. Record and Analyse Data:
   • Calculate the rate of reaction for each temperature using the formula: Rate of Reaction=1Time Taken\text{Rate of Reaction} = \frac{1}{\text{Time Taken}}Rate of Reaction=Time Taken1​
   • Plot a graph of the rate of reaction against temperature to identify trends.

Key Points Of Learning

• Collision Theory: Higher temperatures increase particle energy, leading to more frequent and successful collisions.
• Kinetic Energy: Increased temperature raises kinetic energy, reducing the time for the reaction to complete.
• Graph Analysis: The graph should show that as temperature increases, the reaction rate also increases.

Safety Precautions

• Handle hydrochloric acid with care to avoid skin or eye irritation.
• Use heatproof mats and avoid direct contact with hot equipment.
• Experiment in a well-ventilated area to avoid inhaling fumes.

Example: Thomas Keith Online Independent School

Thomas Keith Online Independent School provides online resources to help students master Core Practical 6. Students can access detailed guides, virtual simulations, and step-by-step instructions. These tools ensure learners gain practical understanding even in an online setting, making chemistry accessible and engaging.

Conclusion

Core Practical 6 is an essential experiment in Edexcel Chemistry that reinforces concepts of reaction rates and temperature effects. It helps students develop analytical skills and understand key principles of collision theory. Schools like Thomas Keith Online Independent School offer excellent resources to support students in mastering this practical, making it achievable even in a remote learning environment.