Time at which the concentration of 'A' reduces half of its initial value is — Chemical Kinetics Chemistry Question

💡 Solution & Explanation

We want [A] = a/2. Using the equation from the previous step: a/2 = a - (b/2)(1 - e^-2kt) => a/2 = (b/2)(1 - e^-2kt) => a/b = 1 - e^-2kt => e^-2kt = 1 - a/b = (b - a)/b. Taking natural log gives -2kt = ln((b - a)/b), so t = (1/2k) ln(b / (b - a)). Therefore, correct answer is C.