Arrange the following in order from least to greatest number of moles of that substance: 12.01g carbon, 7.2 x1023 calcium atoms, 129 magnesium, 649 02.
A. 129 magnesium, 12.01g carbon , 7.2 x1023 calcium atoms, 649 02.
B. 649 02, 7.2 x1023 calcium atoms, 12.01g carbon, 12g magnesium.
C. 7.2 x1023 calcium atoms, 12g magnesium, 12.019 carbon, 649 02.
D. 12.01g carbon , 7.2 x1023 calcium atoms, 129 magnesium, 64 g 02.

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 !

plasma is the state of matter where the substance is ionized and has no definite shape or volume. the fact of being ionized makes the substance a good electrical conductor.