268) For the non equilibrium process, A + B → Products, the rate is first order with respect to A and second order with respect to B. If 1.0 mole each of A and B are introduced in 1 litre of vessel and the initial rate was 1.0 x 10^𕒶 mol⁄litre−sec. The rate (in mol litre⁻¹ sec⁻¹) when half of the reactants have been used?

269) The rate law for a reaction between the substances A and B is given by rate = K[A]ⁿ[B]^m. On doubling the concentration of A and halving the concentration of B, the ratio of the new rate to the earlier rate of the reaction will be as:

270) For a given reaction of first order, it takes 15 minutes for the concentration to drop from 0.8 M litre⁻¹ to 0.4 M litre¹. The time required for the concentration to drop from 0.1 M litre⁻¹ to 0.025 M litre⁻¹ will be:

271) If for a certain first−order reaction, the initial rate is 0.65% min⁻¹, the half life in one hour is:

272) The rate constants k₁ and k₂ for two different reactions are 10^{16e−2000⁄T and 1015e−1000⁄T respectively. The temperature at which ₁ = k₂ is:}