FACTORS AFFECTING RATE OF REACTION
1. CONCENTRA TION
The rate of any chemical reaction increase by increasing concentration of reactant. When concentration is increased, number of molecules also increases due to which collisions and effective collision also increases so that reactants more rapidly react.
The rate of any chemical reaction increase by increasing the temperature. By increasing the temperature K.E of molecules increases there fore number of effective collisions is increased.
Temperature has a pronounced effect on different biochemical process that takes place in food. As a general rate of thumb, the rate of reaction becomes double for every 10K rise in temperature.
A catalyst is a substance that increases or decreases the activation energy of a chemical reaction so that it changes the rate of reaction but it is not consumed.
There are two types of catalyst.
A positive catalyst increases the rate of reaction by increasing the internal energy and decreasing the activation energy.
A negative catalyst decreases the rate of reaction by decreasing the internal energy and increasing the activation energy.
4. SURFACE AREA:
The rate of a heterogeneous chemical reaction can be increased by increasing the surface area of solid reactants. Greater the surface area, the greater will be space for motion of molecules the rate of reaction becomes high. For example the reaction between HCI and powdered zinc is more rapid as compare to its large pieces.
Some chemical reactions require light for their progress are called photochemical reactions,
H2 + Cl2 ———–> 2HCl
CH4 + Cl2 ———–> CH3Cl + HCl
The rate of photochemical reaction is influenced by radiation. Greater the radiation, greater will be the amount of activation energy provided clue to which rate of reaction increases. These reactions do not depend upon concentration of reactants and are zero order reactions.