Question

Half-life of a first order reaction is 30 minutes and initial concentration of reactant is 0.1 M.

What is half-life of the reaction if initial concentration of reactant is doubled? 

Options

• 900 second

• 3600 second

• 600 second

• 1800 second

Answer 1

1800 second

Explanation:

Half-life of a first order reaction is given by formulae `"t"_(1//2) = 0.693/"K"`

Half-life is independent of concentration of reactant.

So, at any value of concentration half-life remains same, i.e.

30 minutes = 30 × 60 seconds = 1800 seconds.