266) If the pH of a Ba(OH)₂ solution is 11, the concentration of this solution is:

267) If K_sp of Ba(OH)₂ is 4 x 10⁻⁹, then the pH of saturated solution of Ba(OH)₂ is:

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: