In this IGCSE Prescribed Practical, we delve into the world of chemical kinetics experiments, investigating the relationship between concentration and temperature on the rate of reaction between hydrochloric acid and sodium thiosulfate. By exploring the principles of reaction kinetics, collision theory, and the rate law, we gain an understanding of how chemical reactions occur and the factors that influence their speed. Through this practical investigation, we calculate activation energy and plot data on a graph to observe trends in reaction rates. Join us in this exciting exploration of chemical kinetics and discover the fascinating world of chemical reactions!