1. The problem statement, all variables and given/known data We performed a lab experiment where we heated (NH4)2CO3 in a test tube and observed the results. The solid compound turned into a gas and evaporated, leaving condensation of a clear liquid on the inside of the test tube. The lab report asks: What is the chemical equation for the reaction when heating (NH4)2CO3? 3. The attempt at a solution At first I thought the answer would be: (NH4)2CO3 = 2NH4 + CO3 But when I looked online to double check my answer, it turns out to be: (NH4)2CO3 = 2NH3 + H2O + CO2 My question is how was I supposed to know the products of this reaction? I can't find any rules regarding this in the chapters we've covered in my book. What are the rules regarding CO3 and NH4 when it comes to heating them? For reference, we've just learned about redox, precipitation, decomposition, synthesis, and single/double replacement reactions. My textbook is: Chemistry: The Central Science, 13th Edition, by Brown, LeMay, Bursten, Murphy, Woodward, and Stoltzfus.