1. The problem statement, all variables and given/known data The following chemical reaction takes place inside a reactor where 80% conversion is obtained with an equimolar mixture of NH3 and O2 fed at the flow rate of 100 mol/h. 4NH3 + 5O2 ⇔ 4NO + 6H2O What are the output rates of all species? There's a diagram shown where ammonia and oxygen are pictured as feed, output are the products, nitrogen monoxide and water, and the unused reactants, ammonia and oxygen. 3. The attempt at a solution The problem wants me to do a mass balance on molecular species. I've just recently started looking at processes involving reactions however and I'm not too sure on how to write balances when reactions are present. If we looked at NH3 for example, input = consumption + output I can denote different variables to represent input and ouput for NH3, but I'm not sure how I'd quantify the consumption of NH3 per unit time. Previously, I would be given the flow rate of one of the outputs of a species and then from stoichiometry I'd be able to get the consumption/generation of any of the species, but I'm not being given it this time. I assume I have to use the 80% conversion somewhere, but that's for equimolar mixtures and I'm not sure how I'd account limiting reactants into the equation to get the appropriate consumption term.