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Rates of reactionTemperature

The speed of a chemical reaction is affected by temperature, concentration, particle size and the presence of a catalyst. It can be calculated by measuring changes in reactants/products.

Part of ChemistryChemical changes and structures

Temperature

At low temperature the particles move slowly and seldom collide. At high temperature the particles move quickly and collide more often.

If the temperature is increased, the particles have more energy and so move quicker. Increasing the temperature increases the rate of reaction because the particles collide more often and with more energy. The higher the temperature, the faster the rate of a reaction will be.

Sodium and chlorine react vigorously when heated, giving an orange flame and producing white sodium chloride.

sodium + chlorine 鈫 sodium chloride

2Na(s) + Cl2(g) 鈫 2NaCl(s)

Watch this video to see the correct procedure for this demonstration.

Look at the graph of the reaction between hydrochloric acid and calcium carbonate. Notice how an increase in temperature leads to an increase in the speed of release of carbon dioxide, but not the total of carbon dioxide released.

Graph of total volume of product against time from start of reaction. The reaction is plotted twice, once at a high temperature and once at a low temperature reaction. Both lines level off at the same volume of product produced, but it takes less time for the high temperature reaction to achieve it.

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