52. Solving a chemistry problem

4. What amount of alkali containing 8% of indifferent impurities should be taken to prepare: a) 1 liter of sodium hydroxide solution with a titer of 0.005 g/ml; b) 500 ml of 0.15 M sodium hydroxide solution; c) 1.5 l of a solution with a titer of sodium hydroxide for calcium oxide equal to 0.0035 g/ml.