Question

what is has life? Derive the relation between life and rate constant for the firsr order reaction.​

Answer 1

Answer:

The half-life of a reaction is the time required for the reactant concentration to decrease to one-half its initial value. The half-life of a first-order reaction is a constant that is related to the rate constant for the reaction: t1/2 = 0.693/k. Radioactive decay reactions are first-order reactions.

Answer 2

Answer:

Half life of a chemical reaction is the time taken for a reaction when half of the initial value has reacted.

Relation between half life and rate constant for first order reaction:-

For first order reaction,

k=(2.303/t) logA'/A

where t is the time, A' is the initial concentration and A is the final concentration.

at t half, A=A'/2

therefore, k=(2.303/ t half) logR'/(R'/2)

=(2.303/t half) log 2

=(2.303/ t half) × 0.301

=0.693/t half

hence, t half= 0.693/ k