C5H12, pentane, is a liquid at room temperature. Can we predict from this information whether C4H10, butane, will be a liquid at room temperature?
A)Yes, it will be a liquid since pentane is a liquid.
B)Yes, it will be a liquid since it contains 4 carbon atoms.
C)We cannot be sure unless we find out its boiling point.
D)We cannot be sure unless we get the boiling point of propane, C3H8.

C. Because for sure C4H10 is gas at room temperature

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 !