So since this is a bimolecular elementary reaction we can use the coefficients as the exponents. In other words, our rate of reaction is equal to KR rate constant times the concentration of hydrogen peroxide times the concentration of iodine. And each of the exponents is one because we have 1 mol of this guy and 1 mol of this guy react to produce these two intermediates. And this is indeed a balanced equation. So once again, the reason we're allowed to find a weight loss so quickly and without experimental results is because step one is an elementary bimolecular reaction with an overall reaction order of two. In other words, this has one coefficient and a second coefficient.