Washing soda has the formula Na2CO3.10H2O. What mass of anhydrous sodium carbonate is left when all the water of crystallization is expelled by heating 57.2 g of washing soda?
(a) If 112 cm3 of hydrogen sulphide is mixed with 120 cm3 of chlorine at STP, what is the mass of sulphur formed? H2S + Cl2 → 2HCl + S (b) Washing soda has the formula Na2CO3·10H2O. What is the mass of anhydrous sodium carbonate left when all the water of crystallization is expelled by heating 57.2 g of washing soda? (c) When excess lead nitrate solution was added to a solution of sodium sulphate, 15.1 g of lead sulphate was precipitated. What mass of sodium sulphate was present in the original solution? Na2SO4 + Pb(NO3)2 → PbSO4 + 2NaNO3 (H = 1; C = 12; O = 16; Na = 23; S = 32; Pb = 207)