giúp minhfv s ạ mình cm nh

Đáp án+Giải thích các bước giải:

 `+)` `Mn_2O_7`

`%`$m_{Mn}=$ $\frac{55.2}{55.2+16.7}.100$`%` `~~` `49,55``%`

`%`$m_{O}=$ $\frac{16.7}{55.2+16.7}.100$`%` `~~` `50,45``%`

`+)` `BaSO_4`

`%`$m_{Ba}=$ $\frac{137}{137+32+16.4}.100$`%` `~~` `58,8``%`

`%`$m_{S}=$ $\frac{32}{137+32+16.4}.100$`%` `~~` `13,734``%`

`%`$m_{O}=$ $\frac{16.4}{137+32+16.4}.100$`%` `~~` `27,467``%`

`+)` `KClO_3`

`%`$m_{K}=$ $\frac{39}{39+35,5+16.3}.100$`%` `~~` `31,836``%`

`%`$m_{Cl}=$ $\frac{35,5}{39+35,5+16.3}.100$`%` `~~` `28,98``%`

`%`$m_{O}$ $\frac{16.3}{39+35,5+16.3}.100$`%` `~~` `39,183``%`