Final answer:
The simplified ratio of product volume to reactant volume in the decomposition of hydrazine is 3:1, calculated based on the proportional relationship between the volume of gaseous substances and the number of moles assuming ideal gas behavior.
Step-by-step explanation:
The simplified ratio of product volume to reactant volume when 20 moles of liquid hydrazine decompose into 60 moles of gaseous products can be determined by looking at the stoichiometry of the balanced chemical reaction and using Avogadro's law, which states that equal volumes of gases at the same temperature and pressure contain an equal number of molecules.
In the absence of information about the conditions of temperature and pressure, we can assume that the gases behave ideally, and thus their volumes are directly proportional to the number of moles. Consequently, if 20 moles of liquid hydrazine produce 60 moles of gaseous products, the simplified ratio of the volume of products to reactants is 60:20, which simplifies further to 3:1.