The half-life gets longer as the initial concentration increases in zero-order reaction.
The amount of time it takes for the concentration of a given reactant to reach 50% of its initial concentration is known as the half-life of a chemical reaction (i.e. the time taken for the reactant concentration to reach half of its initial value).
For zero order reaction:
The half-life is given as:
where k is the rate constant of the reaction and
is the initial concentration.
As we can see that the half-life is directly proportional to the initial concentration. Therefore, when the initial concentration increases the half-life gets longer.
For the first-order reaction,
The half-life is given as:
A first-order reaction's half-life is independent of the initial concentration.
For a second-order reaction,
The half-life is:
The initial concentration is inversely proportional to the half-life, so when the initial concentration increases the half-life will get shorter.
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