Areaction mechanism is defined as the sequence of reaction steps that define the pathway from reactants to products. each step in a mechanism is an elementary reaction, which describes a single molecular event of usually one or two molecules interacting. the rate law for an overall reaction is the rate law for the slowest step in the mechanism, which is directly related to the stoichiometric coefficients of the reactants. the exception to this rule occurs when the slowest step contains intermediates. in these cases, the slowest step is usually preceded by an equilibrium step, which can be used to substitute for the intermediates in the overall rate law. part awhat is the rate law for the following mechanism in terms of the overall rate constant k? step1: step2: a+bb+c⇌→cd(fast)(slow)express your answer in terms of k and the necessary concentrations (e. g., k*[a]^3*[d]).part bconsider the reaction2x2y2+z2⇌2x2y2zwhich has a rate law ofrate= k[x2y2][z2]select a possible mechanism for the reaction. consider the reactionwhich has a rate law ofselect a possible mechanism for the reaction. step1: step2: step3: z2→z+z (slow)x2y2+z→x2y2z (fast)x2y2+z→x2y2z (fast)step1: step2: x2y2+z2→x2y2z+z (slow)x2y2+z→x2y2z (fast)step1: step2: x2y2+z2→x2y2z2 (slow)x2y2z2→x2y2z+z (fast)d step1: step2: 2x2y2⇌x4y4 (fast)x4y4+z2→2x2y2z (slow)e step1: 2x2y2+z2→2x2y2 (slow)