First you need to use correct IUPAC names of sodium sulfate and calcium carbonate.
a. There is no Sulfur in sodium.
b. % C (by mass) in CaCO3 = 100*(atomic mass C/molar mass CaCO3)
c. % O (by mass) in Na2SO4 = 100*(4*atomic mass O/molar mass Na2SO4)
% something in anything = 100*(mass of the something/total mass of the anything). For example, we have a mixture of apples and oranges that has a mass of 10 grams. The apples are 2 grams and the oranges are 8 grams.
% apples = 100*(2/10) = 20%
% oranges = 100*(8/10) = 80%
I'll bet if I gave you the apples and oranges problem you would work it without hesitation. But make the same problem with C in CaCO3 and you need help. It's the same problem. In apples it mass apples/total mass and all of that times 100. In C in CaCO3 it's mass C/total mass and all of that tims 100. Don't get sidetracked by chemical formulae. It's all just math.
Calculate the percentage of:
a) sulphur in sodium
b)carbon in calcium trioxocarbonate (iv)
c) oxygen in sodium tetraoxosulphate(iv)
3 answers
solutionto d question
solution to the problem