Factors affecting Speed of Reaction

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Factors affecting Speed of Reaction by Mind Map: Factors affecting Speed of Reaction

1. Catalyst

1.1. substance that increases the speed of a chemical reaction and remains chemically unchanged at the end of the reaction

1.2. Characteristics

1.2.1. Only small amount needed

1.2.2. Lowers the activation energy

1.2.3. Increases the speed but not the yield of the reaction

1.2.4. Physical appearance may change but not the chemical properties

1.2.5. Not used up during the reaction

1.2.6. Impurities can prevent catalysts from working

1.2.7. Selective in action

1.3. increases the speed of reaction by providing an alternative pathway. (lowers activation energy)

1.3.1. more colliding possess energy equal or greater than the activation energy

1.3.1.1. more collisions between reactant particles

1.3.1.1.1. frequency of effective collisions increase

1.4. Example

1.4.1. Enzymes - biological catalysts

1.4.1.1. Proteins

1.4.1.2. Specific in their actions

1.4.1.3. Sensitive to temperature changes

1.4.1.4. Sensitive to pH change

1.4.2. Iron

1.4.2.1. Haber process

1.4.3. Rhodium & Platinum

1.4.3.1. Catalytic converters

1.4.4. Aluminium oxide or silicon dioxide

1.4.4.1. production of hydrogen in the cracking process

2. Temperature

2.1. When the temperature of a reactant is increased, the speed of the reaction increases

2.2. at high temperatures, reactant particles gain energy, move faster and collide with each other more often

2.2.1. particles possess energy greater or equal to activation energy

2.2.1.1. frequency of effective collisions increases

3. Surface Area

3.1. When the surface area of the solid reactant is increased (size is decreased), the speed of the reaction increases

3.2. solid reactant is broken into smaller pieces, total surface area of reactants increases

3.2.1. more surfaces exposed for other reactant particles to collide

3.2.1.1. more collisions between reactant particles

3.2.1.1.1. frequency of effective collisions increases

4. Pressure

4.1. When the presence of a gaseous reactant is increased, the speed of the reacting increases

4.2. At higher pressures, the particles of gaseous reactants are closer together

4.2.1. more collisions between reactant particles

4.2.1.1. frequency of effective collisions increases

4.3. e.g: Haber process at 250atm

5. Concentration

5.1. When the concentration of a reactant is increased, the speed of the reaction increases

5.2. At higher concentration, the number of reactant particles is greater per unit volume

5.2.1. more collisions between reactant particles

5.2.1.1. frequency of effective collisions increases

6. Effective Collisions

6.1. Increase in frequency of effective collisions increases speed of reaction