The order of reaction is an experimentally determined quanity. It may be zero, poistive, negative, or fractional. The kinetic equation of `nth` order reaction is`k xx t = (1)/((n-1))[(1)/((a-x)^(n-1)) - (1)/(a^(n-1))]` …(i) Half life of `nth` order reaction depends on the initial concentration according to the following relation: `t_(1//2) prop (1)/(a^(n-1))` ...(ii) The unit of the rate constant varies with the order but general relation for the unit of `nth` order reaction is Units of `k = [(1)/(Conc)]^(n-1) xx "Time"^(-1)` ...(iii) The differential rate law for `nth` order reaction may be given as: `(dX)/(dt) = k[A]^(n)` ...(iv) where `A` denotes the reactant. The rate constant for zero order reaction is where `c_(0)` and `c_(t)` are concentration of reactants at respective times.A. `k=(C_(0))/(2t)`B. `k=(C_(0)-C_(t))/(t)`C. `k=ln.(C_(0)-C_(t))/(2t)`D. `k=(C_(0))/(C_(t))`