Question #62d92

1 Answer
Mar 28, 2015

A very important aspect to keep in mind here - you don't actually have 4 So elements on the reactants' side and 12 So elements on the products' side because So is not an element.

You're dealing with the sulfate anion, SO24, which is comprised of 1 sulfur atom, S, and 4 oxygen atoms, O.

This means that you can try to balance the equation either by looking at individual elements, like the other answer attempts to do, or by taking the sulfate anion as a group.

The latter options implies that you have 2 hydrogen atoms, 1 sulfate group, and 1 iron atom on the left side of the equation, and 2 iron atoms, 2 hydrogen atoms, and 3 sulfate groups on the right side of the equation.

H2SO4+FeFe2(SO4)3+H2

Balance the sulfate group first and focus on the rest of the species afterwards. So, you have three times more sulfate groups on the right hand side of the equation multiply the compound that contains the sulfate group by 3 on the left hand side.

3H2SO4+FeFe2(SO4)3+H2

By multiplying this compound by 3, you've increased the number of hydrogen atoms on the left hand side to 6 multiply the hydrogen on the right hand side by 3 to balance them out.

3H2SO4+FeFe2(SO4)3+3H2

Finally, you've got 2 iron atoms on the right hand side multiply the iron by 2 on the left hand side to balance them out

3H2SO4+2FeFe2(SO4)3+3H2