Animation of an experiment measuring the effect of temperature on the rate of a chemical reaction. At 50 degrees Celsius, a Petri dish containing sodium thiosulfate is placed on a dark cross on a white tile. Hydrochloric acid is pipetted into the dish. The reaction proceeds, gradually becoming more opaque, and the time taken for the cross to become invisible is recorded. In the reaction the acid attacks the thiosulfate, forming solid sulfur, which forms a suspension that blocks light. The rate of the production of the sulfur depends on the temperature: it is faster when the the temperature is higher. This is because the reactants are moving more quickly, leading to more collisions, and more of the reactants have the energy required to break chemical bonds.