Question

Is this equation properly balanced? `4Fe + 3O_2 -> 2 Fe_2O_3`?

Answer 1

Yes! (See explanation)

Explanation:

Count how many `Fe` and `O_2` you have on both left and right sides:

You are given:

`4Fe+3O_2 -> 2Fe_2O_3`

`4:Fe:4`
`6:O_2:6`

You actually have the same number of `Fe` on both sides, The same is true for `O_2` so yes this equation is properly balanced.

For added benefit consider the following equation:

`CH_4+O_2-> CO_2+2H_2O`

ASK: Is this equation balanced? Quick answer: No

ASK: So how do we know and how do we then balance it?

DO: Count the number of each atom type you have on each side of the equation:

`1:C:1`
`4:H:4`
`2:O:4`

As you can see everything is balanced except for `O` To balance O we can simply add a coefficient of `2` in front of `O_2` on the left side which would result in `4` `O` atoms:

`CH_4+color(red)(2)O_2-> CO_2+2H_2O`

`1:C:1`
`4:H:4`
`4:O:4`

Everything is now balanced.