63. Solving a chemistry problem

37. Three solutions of K2Cr2O7 are mixed: 300 ml of a solution containing 1.25 g of this salt, 400 ml of a 0.0405 M solution and 250 ml of 0.222 N. solution. The volume of the mixture was diluted with H2O to 1000 ml. Calculate the normal concentration of the resulting solution.