Chapter 5

Chemical Reactions and Stoichiometry

Chemistry is a science largely concerned with reactions, or how molecules of
one or more substances are converted to molecules of a different substance(s).
This chapter discusses formula (or molecular) weight, empirical formulas, and
percent composition; moles and molar mass; balancing chemical reactions and
stoichiometry; and thermodynamics, which is the role of energy in a reaction:
how much energy is given off or absorbed by a reaction and what this can tell us
about the reaction.