A second- order reaction of the type A + B -->P was carried out in a solution that was initially 0.075 mol dm^-3 in A and 0.050 mol dm^-3 in B. After 1.0 h the concentration of A had fallen to 0.020 mol dm^-3. a) Calculate the Rate constant. b) Solve for the half- life of each of the reactants. Hint: Answers are a) 16.22 dm^3/mol*h b) 5.1 × 10^3 s, 2.1 × 10^3 s My Attempt: [A]intial= 0.075 mol dm^-3 [A]= 0.20 x=[A]initial-[A]=0.075-0.20= 0.055 intial=0.050 mol dm^-3 =0.050-x= 0.050-0.055= -0.005 this is where I'm confused because I get a negative for . When I plug that into the integrated rate law, I get a nonreal number. The integrated rate law is kt(initial-[A]initial)=ln([A]intial/[A]intial) Any idea?