Given the chemical equation: 2NO + O2 ---> 2NO2, which of the following statements is incorrect? * A Two mole of NO react with 1 mole of O2 to produce 2 moles of NO2.
B Two moles of NO are stoichiometrically equivalent to 1 mole of O2 gas.
C Two moles of NO are stoichiometrically equivalent to 2 moles NO2.
D Two molecules of NO react with 2 molecules of NO2.

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 !

i think the answer is terrae but not 100 percent sure. ▓▬▬ §