Which of these reactions are redox reactions? Check all that apply. Cd HCl → CdCl2 H2 CuCl2 Na2S → 2NaCl CuS CaCO3 → CaO CO2 2ZnS 3O2 → 2ZnO 2SO2 CH4 2O2 → CO2 2H2O.

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 !

b.

the accuracy of the data.