Mr(AlCl3) = 27 (Al) + 3(35.5) = 27 + 106.5 = 133.5Mr(Fe(OH)3) = 56 (Fe) + 3(16 + 1) = 56 + 51 = 107Mr(PH3) = 31 (P) + 3(1) = 31 + 3 = 34

Итак:

Mr(AlCl3) = 133.5Mr(Fe(OH)3) = 107Mr(PH3) = 34