Question

определите массовую долю элементов: 
1)Na2O
2)K3PO4

Answer 1

1. Na2O = (23*2+16) = 62, 
w (Na2) = 46/62 = 0, 7419 (74,2 %)
w (O) = 16/62 = 0, 258 (25,8 %)

2. K3PO4 = (39*3 + 31 + 16*4) = 212,
w (K3) = 117/212 = 0,552 (55,2 %)
w (P) = 31/212 = 0, 1462 (14,62 %)
w (O4) = 64/212 = 0,3019 (30, 19 %).