WACE Chemistry ATAR study guide
WACE Chemistry ATAR · Work through your exam, one topic at a time.
The WACE Chemistry ATAR is the Western Australian senior secondary course and external examination that produces a chemistry score for university admission. It suits students who intend to study chemistry, pharmacy, medicine, engineering, environmental science or related fields, and who are prepared to combine conceptual understanding with quantitative problem solving. The WACE Chemistry ATAR study guide has 9 sections and about 2,825 words.
01Structure of the Atom and the Periodic Table
The atom is a nucleus of protons and neutrons surrounded by electrons occupying quantised energy levels. Atomic number (Z) fixes the element; mass number (A) fixes the isotope; isotopes differ only in neutron count, so they share chemistry but differ in mass and in nuclear stability.
376 words, about 2 min02Chemical Bonding and Molecular Shape
Ionic bonding transfers electrons between a metal and a non-metal, producing a lattice held by electrostatic attraction; melting points are high and molten or aqueous forms conduct. Covalent bonding shares electron pairs, giving discrete molecules or giant covalent networks.
358 words, about 2 min03Chemical Reactions, Stoichiometry and the Mole Concept
The mole links mass, particle number and gas volume: n = m/M, N = n × 6.022 × 10²³, and at STP one mole of gas occupies 22.4 L (24.5 L at 25 °C and 100 kPa). Balance equations by inspection, then use mole ratios from coefficients; coefficients give the ratio of moles, never the ratio of masses.
324 words, about 2 min04Acids, Bases and Salts
Brønsted–Lowry acids donate protons; bases accept them. Strong acids ionise completely in water; weak acids ionise partially and have an equilibrium constant Ka.
319 words, about 2 min05Redox Reactions and Electrochemistry
Oxidation is loss of electrons (OIL RIG); reduction is gain. Assign oxidation numbers systematically: elements are 0, monatomic ions equal their charge, oxygen is usually −2, hydrogen is +1, and the sum equals the overall charge.
299 words, about 1 min06Thermochemistry and Energy Changes
Enthalpy change ΔH is the heat exchanged at constant pressure. Exothermic reactions release heat (ΔH negative); endothermic absorb heat (ΔH positive).
298 words, about 1 min07Rates of Reaction and Chemical Equilibrium
Rate measures change in concentration per unit time. Collision theory requires sufficient energy and correct orientation; only collisions exceeding the activation energy react.
287 words, about 1 min08Organic Chemistry and Functional Groups
Organic compounds are based on carbon skeletons. Name by the longest chain, number to give the lowest locants, and identify functional group suffixes.
284 words, about 1 min09Chemical Analysis and Laboratory Skills
Filtration separates an insoluble solid; evaporation recovers a dissolved solid; distillation separates liquids by boiling point; chromatography separates by differing affinities for stationary and mobile phases. In paper chromatography, Rf = distance travelled by spot / distance travelled by solvent front; Rf depends on the solvent and temperature.
280 words, about 1 min