Question

First order reaction never goes to complition

Answer 1

the rate of these type of reaction directly proportional to the first order of concentration of the reactants present in the reaction medium. So as the reaction progresses, the conc. of the reactant decreases and consequently rate decreases. when a very less amount of reactant left, theortically reaction is still going on but a very very slower rate. so these type of reactions never achieves completion. It can be shown it mathematically very easily but the chemistry in just this.