Question

A 10g sample of a mixture of calcium chloride and nacl

Answer 1

10 g of sample of mixture of Cacl2 and Nacl is treated to precipitate alll the calcium as CaCo3. this CaCo3 is heated to convert all the Ca to Cao and the final mass of CaO is 1.62g. the precent by mass of Cacl2 in the original mixture

Asked by vedant sharma | 30th Oct, 2014, 03:51: PM

Expert Answer:

CaC03 + heat = CaO + CO2

x 1.62

100 56

x=1.62 x 100/56 = 2.89 g

Cross multiply through the equation and solve for X grams of CaCO3 we get 2.89 grams of CaCO3

Original reaction CaCl2 + Na2CO3 = CaCO3 + 2 NaCl

x 2.89

111 100

x = 2.89 x 111/100=3.2 g

Cross multiply again and solve for X grams of CaCl2, we get 3.2 grams CaCl2

% CaCl2 in original mixture 3.2 grams CaCl2 over l0 gms mixture = .32 or 32%