Revise: Organic Compounds and Macromolecules
What makes a compound organic, hydrocarbons and homologous series, common functional groups and how to test for them, and how monomers link into natural and synthetic macromolecules.
The functional group determines a molecule's characteristic chemistry.
Vinegar (–COOH) is acidic; ethanol (–OH) is not.
Carboxylic acids + carbonate → CO₂ bubbling confirms –COOH.
Adding sodium carbonate to vinegar produces visible bubbles.
A polymer is a long chain of many repeating monomer units.
Ethene monomers link to form polyethylene.
Carbon's catenation (self-bonding) creates enormous structural diversity.
Wood, plastic, fuel, and proteins are all carbon-based.
A homologous series shares a general formula and similar properties.
Octane (n=8): C₈H₁₈.
–OH (hydroxyl), –COOH (carboxyl), –NH₂ (amine) are common functional groups.
All alcohols share the –OH functional group.
Each functional-group test is specific to that group's own reaction.
A negative bubbling test only rules out –COOH, not other groups.
Monomers contain a reactive site (e.g. C=C) that lets them link repeatedly.
Proteins, DNA, and starch are natural polymers too.
Biodegradability depends on whether a matching enzyme exists in the environment.
Cellulose decomposes readily; most plastics persist for decades.