Cho 1 luồng khí CO đi qua ống sứ đựng 0,04 mol hỗn hợp gồm FeO và Fe2O3 đốt nóng. Sau thí nghiệm thu được 4 chất rắn có khối lượng 4,784g. Khi đi ra khỏi ống sứ hấp thu vào dung dịch Ca(OH)2 dư thu được 4,6g kết tủa. Tính % khối lượng FeO và Fe2O3 trong hỗn hợp ban đầu

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

put the answers   and i could answer.

the electron configuration that you gave me has 16 electrons ergo it has 16 protons ergo it is the element sulfur.