Question

A 4.22 g sample of a mixture of CaCl2 and NaCl was treated to precipitate all the Ca as CaCO3, which was then heated and converted to pure CaO. The final mass of the CaO was 0.959 g. What was the percentage by mass of CaCl2 in the original sample?

Answer 1

(0.959 g CaO) / (56.0778 g CaO/mol) x (1 mol CaCl2 / 1 mol CaO) x 
(110.9848 g CaCl2/mol) / (4.22 g) = 0.450 = 45.0% CaCl2

Answer 2

Can u clear out the question.