1. The problem statement, all variables and given/known data Hi, following Wednesday i'm going to produce ammonia in the lab at school but we have 3 questions we have to solve beforehand. The first one asks the global reaction being ammonium chloride reacting with calcium hydroxide to form ammonia, water and calcium chloride, but it also asks WHY this reaction happens. I don't really know how i could explain that. The next question asks me to determine the amount of reactant needed to get 6.40 L ammonia at 20 °C and 1 atm and we work with a 2x excess of Ca(OH)2. 2. Relevant equations The equation is clearly 2 NH4Cl + Ca(OH)2 --> 2 NH3 + CaCl2 + 2 H2O. So we lose as much NH4Cl as we gain ammonia. 3. The attempt at a solution From the ideal gas law i find i gain 0.266 moles of ammonia. Now comes the problem: can i assume NH4Cl is the limitant reactant here as i know Ca(OH)2 is the excess reactant? So i would say the starting amount of NH4Cl is 0.266 moles and as Ca(OH)2 is in 2x excess it's the double meaning 0.532 moles. Did i work correctly or did i completely miss something here? The main confusion to me is the excessive reactant and how to calculate with it. Thanks in advance!