1. 16g氧原子---1mol氧原子---8mol质子
1molD2O---10mol质子
n(D2O)=8/10
=0.8mol
m(D2O)=8*20/10
=16g
2. R2+ --- 2CI- --- RCI2
1mol2mol 1mol
0.2mol0.4mol 0.2mol
M(RCI2) = 19/0.2 = 95g/mol
M(R) = 95 - 71 = 24
3. Ba(OH)2---2H+
1mol2mol
n[Ba(OH)2] = 0.25mol