Определите Массовую долю элемента в следуйщих веществах? KNO3 Ca(H2PO4)2 Ca3(PO4)2 

Mr(KNO3)=39+14+(16*3)=101  w(K)=39/101*100=39%  w(N) =14/101*100=14%  w(O3)=48/101*100=47%   Mr(Ca(H2PO4)2)=40+(2+31+64)*2= 234  w(Ca)=40/234*100%=17% w(H2)=2*2/234*100%=2% w(P)=31*2/234*100%=26% w(O4)=64*2/234*100%=55% 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%