Question

The half-life of a first-order reaction A → products is 50 s. Calculate: (a) the rate constant and (b) the concentration of the reactant at 25 s after the initiation of the re- action, if the initial concentration of the reactant is 0.5 mol/L. 

Answer 1

Rate =k×[A]

50s ×1M

= $=5.0×10 ^{−5} molL {−1} s {−1}$