Learn about condensation polymers: formed when a diol reacts with a dicarboxylic acid, producing a polyester and water. These polymers are used in fabrics and biodegradable materials like biopolyesters, which decompose quickly, helping to reduce landfill waste.

Learn about addition polymers: formed by joining monomers with C=C bonds, such as ethene to polyethene. Polymers are non-biodegradable, causing environmental issues like landfill buildup and ocean pollution. Disposing involves burning, which releases harmful gases, or recycling, which is labour-intensive but eco-friendly.

Learn about esters, formed when an alcohol reacts with a carboxylic acid in the presence of an acid catalyst like sulfuric acid. Esters are volatile, have fruity smells, and are used in perfumes and flavorings. For example, ethyl ethanoate, made from ethanol and ethanoic acid, smells faintly of pineapples.

Learn about alcohols and carboxylic acids. Alcohols are used as fuels and solvents. They can be oxidized to carboxylic acids, such as ethanoic acid in vinegar. Ethanol is produced industrially from ethene or via fermentation. Carboxylic acids react with metals and carbonates, forming salts.

Learn about alkanes and alkenes: alkanes are saturated hydrocarbons with single bonds, while alkenes are unsaturated hydrocarbons with carbon-carbon double bonds. Alkanes undergo substitution reactions with halogens under UV light, while alkenes participate in addition reactions, forming dihaloalkanes. Bromine water distinguishes alkenes by turning colorless, while alkanes remain unchanged.

Burning hydrocarbons produces carbon dioxide and water (complete combustion) or carbon monoxide and soot (incomplete combustion). Carbon monoxide is toxic, while nitrogen oxides and sulfur dioxide contribute to acid rain. Cracking converts long-chain hydrocarbons into shorter, useful fuels.

Learn about crude oil: a mixture of hydrocarbons extracted from underground reservoirs. Fractional distillation separates crude oil into fractions based on boiling points, producing fuels like gasoline, diesel, and kerosene. As carbon chain length increases, fractions become darker, more viscous, and have higher boiling points.

Learn about organic compounds: hydrocarbons are made of carbon and hydrogen only, forming groups like alkanes and alkenes. Represent organic molecules using various formulas, and understand homologous series, functional groups, and isomerism. Naming follows IUPAC rules based on carbon chains and functional groups. Organic reactions include substitution, addition, and combustion, producing compounds like chloromethane and ethanol.

Learn about dynamic equilibrium: in a closed system, a reversible reaction reaches dynamic equilibrium when the forward and backward reactions occur at the same rate, keeping concentrations constant. Changes in temperature or pressure shift the equilibrium position based on Le Chatelier’s principle, while catalysts speed up the reaction without affecting the equilibrium position.

Learn about reversible reactions: these reactions can proceed in both directions, represented by the symbol ⇌. Examples include the heating of ammonium chloride, which decomposes into ammonia and hydrogen chloride, and the dehydration of hydrated copper sulfate, which turns white when heated and reverts to blue upon rehydration.