Experiment: The rate of reactions and temperature

////Experiment: The rate of reactions and temperature

Experiment: The rate of reactions and temperature

Relationship between temperature and rate of reaction. Image credit bu.edu

Relationship between temperature and rate of reaction. Image credit bu.edu

ZIMSEC O Level Combined Science Notes:Experiment: The rate of reactions and temperature

Aim:  To find the effect of temperature on the rate of reaction: using hydrochloric acid and sodium thiosulphate

Materials: flask, measuring cylinder, stop watch/watch/stop watch app, thermometer with a 0-100°C scale, burner, tripod, sheet of white paper, dilute hydrochloric acid, sodium thiosulphate solution

Methods

  1. Mark the sheet of paper with an X
  2. Measure out 10cm of sodium thiosulphate solution into a flask
  3. Add 40 cm3  of distilled water into the solution
  4. Warm the solution gently to about 25°C
  5. Add 5 of hydrochloric acid
  6. Note the temperature and the time
  7. Swirl the contents of the flask and place the flask over the on the paper
  8. Observe the by looking down vertically through the solution
  9. Take note of the time it takes for the to “disappear” i.e. the time it takes for the to be invisible when viewed through the solution
  10. Rinse the flask and repeat the experiment by heating the sodium thiosulphate solution to 30°C,40°C, 50°C and 60°C respectively before adding the acid
  11. Tabulate the results
  12. Plot the results onto a graph

Observations and results

Rate of reaction and temperature. Image credit bbc

Rate of reaction and temperature. Image credit bbc

  • The higher the temperature of the sodium thiosulphate solution the faster the reaction
  • At some point the rate of reaction stops increasing even though the temperature is increased
  • This is because at this temperature the particles of the reagents would be colliding at a maximum possible rate i.e the reaction is almost instantaneous/as fast as it can be

Conclusion

  • Increasing the temperature of a reaction/reagents results in an increase in the rate of reaction
  • This is because as temperature is increased the particles of the reagents move faster and collide at a higer rate
  • Also particles can overcome the reaction energy barrier at a faster rate
  • This rate cannot be sped up indefinitely at a certain point the rate of reaction stops increasing even though temperature is increased
  • This is known as the optimum temperature

To access more topics go to the Combined Science Notes page.

By |2017-01-17T11:13:46+00:00April 20th, 2016|Notes, O Level Science Notes, Ordinary Level Notes|Comments Off on Experiment: The rate of reactions and temperature

About the Author:

He holds an Honours in Accountancy degree from the University of Zimbabwe. He is passionate about technology and its practical application in today's world.
%d bloggers like this: