I am trying to figure out how todo this problem.?

Question

can you explian how to do it?


Question 1:
What is the percent of oxygen in Ca3(PO4)2?

Question 2:
What is the percent of sulfur in ammonium sulfate?

Question 3:
What is the percentage of iron in ferric sulfate?

Answer 1

Q1)
Ca3 (PO4)2 (MW)molecular weight = 3*40 + 2 * (95) = 310 the oxygen weight is 16*4 = 64 .so % of O is (64/310) *100 = 20.6%

Q2)
SO4 (NH4)2 ---> MW = 32+4*16+ 2*18 =132 Mass of sulfur 32
hence % S = 100*32/132 =24.2

Q3)

Fe2 (SO4)3 ----> MW = 56*2+96*3=400

% of iron 100*112/400 = 28%

Answer 2

the molecular weight of calcium phosphate=(Ca3(PO4)2
%age of oxygen=[8 times the atomic weight of oxygen/molecular weight of calcium phosphate] times 100

2.molecular weight of ammonium sulphate(NH4)2SO4
=[%age of sulphur=atomic weight of sulphur/molecular weight of ammonium sulphate] times 100

3.molecular weight of ferric sulphateFe2(SO4)3=
%age of iron in ferric sulphate=[2 timesatomic weight of iron/molecular weight of ferric sulphate] times 100