# In the equation, I_2 + O_2 -> I_4O_9 what should be the coefficients of the reactants and products?

May 14, 2016

$4 {I}_{2} + 9 {O}_{2} \to 2 {I}_{4} {O}_{9}$
We require a multiple of $9$ times the ${O}_{2}$ in order to get a multiple of ${O}_{9}$ on the right hand side.
Then $9 {O}_{2}$ contains $2 \times 9$ oxygen atoms, so we need a multiplier $2$ on the right hand side.
Then the right hand side has $8$ iodine atoms, so we need a multiplier of $4$ on the ${I}_{2}$ on the left hand side.