Stage 2 Chemistry Curriculum Concepts

Comprehensive vocabulary flashcards covering the core chemistry concepts across Topics 1 to 4: Monitoring the Environment, Managing Chemical Processes, Organic and Biological Chemistry, and Managing Resources.

Greenhouse effect

The process by which certain atmospheric gases, such as carbon dioxide and methane, keep the Earth's atmosphere warmer than it would be without them.

Ocean acidification

The ongoing decrease in the pH of the Earth's oceans caused by absorbing elevated levels of carbon dioxide from the atmosphere.

Photochemical smog

Atmospheric pollution produced in the troposphere through reactions involving nitrogen oxides and ozone generated from high-temperature combustion engines and furnaces.

Catalytic converter

A motor vehicle device that reduces atmospheric pollution by reducing the quantities of emitted nitrogen oxides.

Titration

A volumetric analytical technique used to determine the unknown concentration of a reactant solution in a chemical reaction using stoichiometry and precise glassware rinsing.

Chromatography

An analytical method that separates components of a mixture based on their rates of movement caused by differences in interaction strengths with a stationary phase and a mobile phase.

Ion chromatography

A chromatographic technique (also termed ion exchange chromatography) used to remove cations or anions from a mixture by exchanging them with ions attached to the surface of a resin.

Atomic absorption spectroscopy (AAS)

A quantitative analytical technique based on electron transfer between atomic energy levels that measures the unique wavelengths of radiation absorbed by an element.

Chemical equilibrium

A dynamic state reached over time in a closed, reversible chemical reaction system at fixed temperature where reactant and product concentrations remain constant.

Equilibrium constant ($K_c$)

A numerical value at a specified temperature that relates the equilibrium concentrations of reactants and products for a homogeneous system.

Le Châtelier's principle

The principle stating that if a change in concentration, pressure, or temperature is imposed on an equilibrium system, the system adjusts its position to counteract that change.

Condensation reaction

A chemical reaction in which two organic molecules join to form a larger molecule with the simultaneous elimination of a small molecule, such as water.

Carbohydrates

Naturally occurring sugars and their polymers defined as polyhydroxy aldehydes, polyhydroxy ketones, or substances that yield these compounds upon hydrolysis.

Triglycerides

Edible fats and oils formed as triesters of propane-1,2,3-triol (glycerol) and three carboxylic acid molecules.

Micelles

Spherical structures formed by carboxylate ions having both hydrophobic and hydrophilic regions that allow non-polar substances to dissolve in an aqueous medium.

Peptide links

The secondary amide groups ($-\text{CONH}-$) formed via condensation reactions that link amino acid monomers in a protein polymer chain.

Biofuels

Renewable fuels produced by present-day biological processes, such as bioethanol and biodiesel.

Fuel cells

Galvanic cells that directly convert chemical energy to electrical energy, characterized by an ongoing, continuous supply of electrode reactants.

Flocculation

A water treatment step where finely suspended, negatively charged clay particles aggregate into larger sedimentable clumps upon the addition of highly charged cations (such as aluminium ions) or polymers.

Hard water

Water that contains high concentrations of dissolved $Ca^{2+}$ and $Mg^{2+}$ ions, which impairs soap lathering and leads to precipitate formation.

Zeolites

Natural and modified aluminosilicate minerals used in water purification and water softeners to remove hardness ions via cation exchange.

Reverse osmosis

A filtration technique where saline water is forced under high pressure through a semi-permeable membrane to produce potable water.

Eutrophication

The degradation of water bodies caused by excessive leaching of nitrogen and phosphorus nutrients from soils, leading to dense plant growth and subsequent ecological depletion.

Thermoplastic polymers

Plastics consisting of linear or branched chains with only secondary interactions between chains, allowing them to soften and melt when heated.

Thermoset polymers

Rigid polymers containing extensive covalent cross-linking between polymer chains that decompose rather than soften or melt upon heating.

Composite materials

Materials produced by combining two or more distinct constituent materials to yield physical and chemical properties different from the individual components.