6.5: Stoichiometry Applications

In this chapter, we have introduced the basics of stoichiometry. These ideas are foundational to much of how quantitative chemistry is done, particularly in hands on settings such as laboratories. But there are many more applications to these ideas. We will be exploring these additional applications in later chapters. For example, we have assumed so far that we are only considering reactions in which we are able to determine the mass of reactants and products. It turns out that in some experimental setups, that mass is not the most convenient thing to measure about a reactant or product. In later chapters we will consider how we might use properties of gases or solutions such as volume, pressure, temperature, and/or concentration in order to determine moles instead of always starting with mass. There is a hint of how this might work within the mole roadmap included in one of the subsections. As you consider this mole roadmap, make sure that you can apply the ideas related to moles and mass for now. We will introduce the other ideas later.

In addition to looking at chemical reactions in a variety of physical states, we also might want to consider a few other things with stoichiometry. For example, everything we have considered so far has only included information about one of the reactants when often there are 2 or more. In order to consider these situations, we must use the limiting reactant concept. Another consideration is whether the chemical reaction made as much product as we might have expected. There are a variety of things that must be considered for a chemical reaction in order to decide on this, however in order to have a conversation around whether or not the reaction worked we need to understand the concept of theoretical yield and percent yield. These 3 concepts (limiting reactant, theoretical yield, and percent yield) will be introduced very briefly here and explored in greater detail in a later chapter.