Initial concentration of HCl, O2, Cl2 involved in the reaction: 4HCl (gas) + O2 (gas) = 2Cl (gas) + H2O (gas); respectively: 4.2; 1.8; 0.01 mol/l. Calculate the concentration of all the reactants after the oxygen concentration decreases to 1 mol/l. What mass fraction of each of the starting materials will react at that moment?
