Rate of Reactions

Effective collision

1. sufficient energy

2. right orientation

methods to measure rate of reaction

1. volume of gas produced per unit time

2. decrease in mass when gas is released per unit volume

（Factors) Size of reactant particles

1. Greater exposed surface area to volume ration

2. Frequency of effective collision between reacting particles increases

3. Rate of reaction increases

Concentration & Pressure

1. More particles per unit volume

2. Frequency of effective collision between reacting particles increases

3. Rate of reaction increases

Temperature

1. Higher kinetic energy and move faster

2. More particles have more than or equal energy to overcome activation energy

3. Frequency of effective collision between reacting particles increases

4. Rate of reaction increases

Catalyst

1. Speeds up reaction by providing an alternative pathway

2. More particles have sufficient energy to overcome lower activation energy

3. Frequency of effective collision between reacting particles increases

4. Rate of reaction increases

characteristics of catalyst

1. Yield remains unchanged throughout

2. Remains chemically unchanged

3. only small amount of catalyst is required

4. Transition metals due to their variable oxidation states

enzymes

Biological catalysts to increase rate of chemical reactions

characteristics —> highly specific/sensitive (temp & pH changes)/ selective