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Rates of reaction - (CCEA)Measuring rates of reaction

The rate of reaction increases when reactant particles successfully collide more frequently. Temperature, reactant concentration, size of solid reactant particles (surface area) and catalysts can all affect the reaction rate.

Part of Combined ScienceFurther chemical reactions, rates and equilibrium, calculations and organic chemistry

Measuring rates of reaction

The can be found by measuring the amount of formed, or the amount of product lost, over a certain period of time.

The of a solid product is measured in grams, while the of a gaseous product is measured in cm3.

Rate is most often calculated using the equation: rate = \( \frac {1}{time}\) where the time is the time for the reaction to reach a certain point or the time for the reaction to be completed. The units of rate calculated in this way are s-1.

Measuring the rate when a gas is produced

The apparatus you use depends on the nature of the product being measured.

  • the mass of a substance - solid, liquid or gas - is measured with a balance.
  • the volume of a gas is usually measured with a gas syringe (or sometimes with an upside-down measuring cylinder).
A sealed conical flask connected to a gas syringe. The flask contains a reaction mixture that is giving off bubbles of gas.