For the reaction A + B → C, the following data were obtained. In the first experiment, when the initial concentration of both A and B is 0.10 M, the observed initial rate of formation of C is 1 × 10'4 mole litre'1 minute'1. In the second experiment when the initial concentration of A and B are 0.10 and 0.30 M, the initial rate is 9 × 10'4 mole litre'1 minute'1. In the third experiment, the initial concentration of both A and B is 0.30M and the initial rate is 2.7 × 10'3 mole litre'1 minute'1, then the value of specific rate constant for this reaction is