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

May 11, 2017

Yes! (See explanation)

#### Explanation:

Count how many $F e$ and ${O}_{2}$ you have on both left and right sides:

You are given:

$4 F e + 3 {O}_{2} \to 2 F {e}_{2} {O}_{3}$

$4 : F e : 4$
$6 : {O}_{2} : 6$

You actually have the same number of $F e$ on both sides, The same is true for ${O}_{2}$ so yes this equation is properly balanced.

For added benefit consider the following equation:

$C {H}_{4} + {O}_{2} \to C {O}_{2} + 2 {H}_{2} O$

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:

$C {H}_{4} + \textcolor{red}{2} {O}_{2} \to C {O}_{2} + 2 {H}_{2} O$

$1 : C : 1$
$4 : H : 4$
$4 : O : 4$

Everything is now balanced.