For a FIRST order reaction, the halflife is 100 seconds. How much time will the reactant take to become 1//4 of the initial concentration? (A) 200sec (B) 300sec (C) 400sec (D) 500sec In the reaction A+B+C rarr Products. it is found to obey the rate Law: r=-(dA)/(dt)=K[A]^(2)[B]^(3//2)[C]^(-1//2) The overall rate of reaction is (A) 7//2