Solid-fuel rockets are a central feature in the world’s space exploration programs, including the new Space Launch System being developed in the United States by the National Aeronautics and Space Administration (NASA) to replace the retired Space Shuttle fleet (see image below).
The engines of these rockets rely on carefully prepared solid mixtures of chemicals combined in precisely measured amounts. Igniting the mixture initiates a vigorous chemical reaction that rapidly generates large amounts of gaseous products. These gases are ejected from the rocket engine through its nozzle, providing the thrust needed to propel heavy payloads into space.
Both the nature of this chemical reaction and the relationships between the amounts of the substances being consumed and produced by the reaction are critically important considerations that determine the success of the technology.
In this tutorial, we are going to delve into the heart of chemistry. We will describe how to symbolize chemical reactions using chemical equations, how to classify some common chemical reactions by identifying patterns of reactivity, and how to determine the quantitative relations between the amounts of substances involved in chemical reactions—that is, the reaction stoichiometry.
We will learn ways of representing molecules and how molecules react. To do this, we will even think about “how many” of a molecule we have using a quantity called a “mole”. In Chemistry 101: Introduction to Matter, we have already discussed the mole at length. If you need to review some of the concepts treated in that tutorial so that you can easily follow this one, feel free to do so.