In the following reaction: C6H6 + Br2 → C6H5Br + HBr

Assume 1.25 moles of C6H6 react with sufficient bromine, how many moles of C6H5Br should form?

2.50 mol
5.00 mol
0.625 mol
1.25 mol

1.25mol

Explanation:

The equation you gave is balanced and everything is in a 1:1:1:1 ratio. Because there is excess bromine, the reaction can proceed until completion which will give you 1.25 mol C6H5Br

whats the meaning of /

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 !