20 баллов. Найти массовую долю вещества:
1)PO5
2)KNO3
3)CaPO4

Мr(Р2О5) = 31*2 + 16*5 = 142
W(P) = 31 * 2 / 142. *100 = 44
W(O)=16*5 / 142. *100 = 56

Mr(KNO3) = 39+14+16*3 = 101
W(K) = 39*1 / 101. *100 =39
W(N) = 14*1 / 101. *100 = 14
W(O) = 16*3 / 101. *100 = 47

Mr(Ca3(PO4)2) = 40*3 + 31*2 + 16*8 = 310
W(Ca) = 40*3 / 310. *100 = 39
W(P) = 31*2 / 310. *100 = 20
W(O) = 16*8 / 310. *100 = 41