A sample of sodium trioxocarbonate(IV) containing sand was dissolved in excess tetraoxosulphate (V) acid and filtered to obtain solution A. B is a solution containing 0.096mol of NaOH per dm³ of solution. Solution A was poured into the burette and titrated against 25cm³ portion of B using methyl orange as indicator. The exercise was repeated to obtain consistent titre values. Assuming that the average titre value is 19.60cm³. Calculate i) The concentration of excess tetraoxosulphate (IV) acid in A in mol/dm³ ii) The mass of sand in the sample if 9.00g of the impure sodium trioxocarbonate (IV) reacted with 1dm³ of 0.10M solution of the acid [H=1.0, C=12, O=16.0, Na-23.0, S=32.0]
