Question

How do you balance this equation? `MnO_2 + Al -> Mn + Al_2O_3`

Answer 1

`3MnO_2+4Al -> 3Mn+2Al_2O_3`

Explanation:

Since we have a multiple of `3` oxygens on the right hand side we require a multiplier of `3` on the left hand side.

If we have `3MnO_2` on the left hand side, then that is a total of `3` manganeses and `6` oxygens, requiring `3Mn+2Al_2O_3` on the right hand side.

Then we need `4` aluminiums on the left hand side.

Hence the balanced form of the equation is:

`3MnO_2+4Al -> 3Mn+2Al_2O_3`