Масовая частка у сполуках Ca3(PO4)2 Fe2(SO4)3
Mr(Ca3(PO4)2)=120+(31+64)*2=310
w(Ca3)=120/310*100%=39%
w(P)=31*2/310*100%=20%
w(O4)=64*2/310*100%=41%
W-(Fe2)= 112/400=28%
W(S)=96/400=24%
W(O)=192/400=48%