The given plots represents the variation of the concentration of a reactant R with time for two different reactions (i) and (ii). The respective orders of the reactions are:

Concept:The main difference between first order and zero order kinetics is that the RATE of first order kinetics depends on the concentration of one reactant whereas the rate of zeroth order kinetics does not depend on the concentration of reactants.In graph (i), ln [Reactant] vs time is linear with positive intercept and negative slope. Hence it is 1st order.In graph (II), [Reactant] vs time is linear with positive intercept and negative slope. Hence, it is zero order.R ⟶ PFor zero order reaction,Integrated form of the Zeroth Order Rate Law,[At] = - K0 t + [A0]For First order reaction,Integrated form of the First Order Rate Law\({{\rm{K}}_1} = \frac{1}{{\rm{t}}}\log \LEFT( {\frac{{{{\rm{A}}_0}}}{{{{\rm{A}}_{\rm{t}}}}}} \right)\) K1t = log [A0 ] – log [At]log [At] = - K1t + log [A0 ]