Summary of session 5

• In a chemical reaction, the total mass of the reactants equals the total mass of the products.
• Balanced chemical equations are used to concisely represent chemical reactions.
• The structural formulas of organic molecules can be divided into the carbon-hydrogen framework or skeleton, and the functional group(s). In the first approximation, the functional groups are the sites where reaction occurs, the framework remaining unreactive.
• The above approximation works best when the framework consists of saturated carbon atoms.