Надо определить массовую долю элемента в веществе

1) SO3

2) SO2

3) CO

4) CO2

1) SO3

Mr (SO3) = 80

W (S) = 80:32=0.4=40%

W (3O) = 80:48=60%

2) SO2

Mr (SO2) = 64

W (S) = 32:64=0.5=50%

W (2O) = 32:64=0.5=50%

3) CO

Mr (CO) = 28

W (C) = 12:28=0.4=40%

W (O) = 16:28=0.64≈0.6=60%

4) CO2

Mr (CO2) = 44

W (C) = 12:44=0.27≈0.3=30%

W (2O) = 32:44=0.72≈0.7=70%