Ответ:

Mr1 =D*Mr2

D=17.75

Mr2 (H2) =2

Mr1 =17.75*2=35.5

Mr(O2)=32

Mr(O3)=48

32. 48

35.5

12.5. 3.5

12.5+3.5=16

16.-------------100%

12.5-----------x%. x=1250/16=78.125(O2)

100-78.125=21.875%(O3)