Chemical Reactions and First Nations Plant Processing Vocabulary

A complete vocabulary review set covering chemical reactions, energy changes, covalent bonding, redox processes, and First Nations Australian plant detoxification and fermentation methods.

Enthalpy ($H$)

The stored energy contained within the chemical bonds of a substance.

Change in Enthalpy ($\Delta H$)

The change in stored chemical energy during a reaction, calculated as $\Delta H = H(\text{products}) - H(\text{reactants})$.

Exothermic Reaction

A reaction that releases heat energy to its surroundings, causing the temperature of the surroundings to increase ($\Delta H$ is negative).

Endothermic Reaction

A reaction that absorbs heat energy from its surroundings, causing the temperature of the surroundings to decrease ($\Delta H$ is positive).

Activation Energy ($E_a$)

The initial energy required to start a chemical reaction.

Covalent Bond

A chemical bond formed by a shared pair of electrons between non-metal atoms.

Covalency

The number of electrons an atom shares when bonding covalently with other non-metal atoms to obtain a full outer shell.

Lone Pairs

Pairs of non-bonding outer-shell electrons present on an atom in a molecule.

Double Bond

A covalent bond formed when two pairs of electrons are shared between two atoms.

Triple Bond

A covalent bond formed when three pairs of electrons are shared between two atoms.

Combustion Reaction

An exothermic chemical reaction in which a substance reacts with oxygen, releasing heat and light.

Combination Reaction

A reaction in which two reactants combine to form a single product, expressed as $X + Y \rightarrow XY$.

Decomposition Reaction

A reaction in which a single reactant breaks down to form more than one product, expressed as $XY \rightarrow X + Y$.

Neutralisation Reaction

A reaction between an acid and a base that produces a salt and water ($\text{acid} + \text{base} \rightarrow \text{salt} + \text{water}$).

Redox Reaction

A chemical reaction involving the transfer of electrons from one substance to another.

Oxidation

A chemical process involving the loss of electrons.

Reduction

A chemical process involving the gain of electrons.

OIL RIG

A mnemonic acronym for 'Oxidation Is Loss, Reduction Is Gain' of electrons.

LEO says GER

A mnemonic phrase standing for 'Loss of Electrons is Oxidation – Gain of Electrons is Reduction'.

Oxidising Agent

A substance that causes another substance to undergo oxidation while undergoing reduction itself by gaining electrons.

Reducing Agent

A substance that causes another substance to undergo reduction while undergoing oxidation itself by losing electrons.

Metal Displacement Reaction

A redox reaction in which a more reactive metal transfers electrons to the cations of a less reactive metal in solution.

Electrochemical Series

A series ranking metals according to their relative reactivity and standard electrode potential ($E^0$) values at $25\,^{\circ}\text{C}$.

Anaerobic Respiration

A metabolic process used by unicellular organisms, as well as human and plant cells in the absence of oxygen, to convert carbohydrates into products like gases, alcohol, and acids.

Cycad

A palmlike plant with a thick woody trunk on which a crown of large, compacted leaves sits.

Cycasin

A toxic substance found in cycads that can cause cancer and damage the nervous system.

Detoxify

To remove toxic (poisonous) substances.

Leaching

The process of a soluble substance being removed from a solid after coming in contact with a liquid, such as water.

Toxins

Substances created by plants and animals that are poisonous to humans.

Fermentation of Glucose

An anaerobic reaction where glucose is converted into ethanol and carbon dioxide using yeast ($\text{C}_6\text{H}_{12}\text{O}_{6(aq)} \xrightarrow{\text{yeast}} 2\text{C}_2\text{H}_5\text{OH}_{(aq)} + 2\text{CO}_{2(aq)}$).

First Nations Fermentation Plants

Australian native plants—including cider gums, banksias, lemon myrtle, acacias, and Tasmanian pepperberry—used by First Nations Australians for fermentation.