Rate Of Reaction

Factors affecting rate of reaction

• Concentration: doubling doubles rate of reaction (directly proportional)

• Surface Area: smaller particles = faster rate (directly proportional)

• Temperature: 10 degree rise doubles rate

• Catalyst: substance that speeds up reaction but is not used up

• Nature of reactants: ionic compounds react quickly, covalent compounds react slowly

Calculating rate of reaction

Average rate: total volume produced ÷ time = cm² per minute

Instantaneous rate: rise ÷ run

Theories of Catalysis

1. Activation energy: catalysts provide alternative pathway with lower activation energy

2. Surface adsorption: reactants adsorbed into surface of catalyst and product released when formed

3. Intermediate compound formation: catalysts form unstable intermediate compound with the reactants which decomposes into products

Homogeneous: reactants and catalysts in same phase

Heterogeneous: reactants and catalysts in different phases

Autocatalysis: product of reaction catalyses reaction