Concentration of 'A' at time 't' is — Chemical Kinetics Chemistry Question

💡 Solution & Explanation

Rate = -1/2 d[B]/dt = k[B]. Solving this, d[B]/[B] = -2k dt, giving [B] = b·e^-2kt. The amount of B reacted is b - b·e^-2kt. By stoichiometry, the amount of A reacted is half of B reacted, which is (b/2)(1 - e^-2kt). Thus, remaining [A] = a - (b/2)(1 - e^-2kt). Therefore, correct answer is C.