A first order reaction takes 100 minutes for completion of 50 % of the reaction. Find the time when 75 % of reaction will be completed.

A first order reaction takes 100 minutes for completion of 60% of the reaction. Find the time when 90% of reaction will be completed.

A first order reaction takes 20 minutes for 25% decomposition . Calculate the time when 75% of the reaction will be completed. (Given : log 2 = 0.3010, log3 = 0.4771 log4 = 0.6021 )

A first order reaction takes 60 minutes for 75% completion. Determine its half- life.

A first order reaction takes 10min to complete 40% of the reaction. Another first order reaction requires 15min to complete 60% of the reaction. Calculate the ratio of the rate constants of the two reactions.

Show that for any first order reaction, the time required for the completion of 99.9% of the reaction is 10times the half-life of the reaction.

The initial concentration of the reactant in a first order reaction is a . It takes time t for the completion of noth fraction of the reaction. Will it take time 2t for the completion of the same fraction if the initial concentration of the reactant is made twice ?

For a first order reaction the ratio of times to complete 99.9% and half of the reaction is

A first order reaction takes 40 min for 30% decomposition . Calculate t_(1//2) .

A first order reaction takes 46 min for its 99% completion . How much time did it take for its 75% completion -

Half - life of a first order reaction is 15 min . Calculate rate constant of the reaction and the time required to complete 80% of the reaction. If the initial concentration of the reactant is doubled , how long will it take to reach 50% completion ? Give reason.