During a titration, 240 ml of NaOH reacted completely with 100 ml of `H_2SO_4` solution. The weight of `H_2SO_4` taken was 9.8 g.
(i) What is the molarity of the NaOH used?
(ii) Calculate the amount of NaOH dissolved in solution.
(iii) How many grams of NaOH should be added to the original NaOH solution to make one litre of 0.5M NaOH solution?
(Molecular mass of NaOH is 40g/mol and molecular mass of `H_2SO_4` is 98 g/mol.)