Calculate the rate constant of first order reaction if half life of reaction is 40 minutes.

Identify rate law expression for $$2 \mathrm{NO}_{(\mathrm{g})}+\mathrm{Cl}_{2(\mathrm{~g})} \rightarrow 2 \mathrm{NOCl}_{(\mathrm{g})}$$ if the reaction is second order in $$\mathrm{NO}$$ and first order in $$\mathrm{Cl}_2$$.

For a reaction $$\mathrm{A}+\mathrm{B} \rightarrow$$ product, if $$[\mathrm{A}]$$ is doubled keeping $$[\mathrm{B}]$$ constant, the rate of reaction doubles. Calculate the order of reaction with respect to A.

Calculate the rate constant of the first order reaction if $$80 \%$$ of the reactant reacted in 15 minute.