10. Solving a chemistry problem

12. Three solutions of potassium dichromate 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 a 0.222 N solution. The volume of the mixture was diluted with water to 1000 ml. Calculate the normal concentration of the resulting solution in oxidation reactions.