Ответ:

W(H2)=2%

W(Cr)=47%

W(O7)=51%

Ответ:

Объяснение:

Mr(H2Cr2O7) = 1*2 + 52*2 +16*7 =218

W(H) = Ar(H) *n / Mr(H2Cr2O7)  *100% = 1*2 / 218  *100% =1%

W(Cr) = Ar(Cr) *n / Mr(H2Cr2O7)  *100% = 52*2 / 218  *100% =48%

W(O) = Ar(O) *n / Mr(H2Cr2O7)  *100% = 16*7 / 218  *100% = 51%