A compound has the following composition by weight ; Na = 18.60 %, * = 25.80 %, H = 4.02 % and O = 51.58 % Assuming that all the hydrogen atoms in the compound are part of water of crystallization, the correct molecular formula of the compound is
(A) Na2S2O3 .3H2O
(B) Na2SO4 .5H2O
(C) Na2SO4 .10H2O
(D) Na2S2O3 .5H2O
