Redox Key Words

balanced

number of atoms for each element in the reaction and the total charge are the same for both the reactants and the products

disproportionation

redox reaction in which the same element is both oxidized and reduced.

electron transfer

loss or gain of electrons between atoms / ions

half equation

electron-half-equations / half-equations / ionic-half-equations / half-reactions: Electrons are being lost (oxidation) or electrons are being gained (reduction): any redox reaction is made up of two half-reactions

halide

ion formed by halogen eg chloride Cl-, bromide Br-, iodide I-

halogen

non-metal element from group 17 e.g. chlorine Cl2, bromine Br2, iodine I2

ion

an atom or a group of atoms that has acquired a charge by gaining or losing one or more electrons e.g. dichromate Cr2O7

observations

changes that can be seen, heard or felt e.g. a colour change or gas bubbles

oxidant

a substance that oxidises another substance; an oxidising agent

oxidation number

oxidation state; sort of electronic book-keeping system to help work out what has been oxidised or reduced

oxidation

loss of electrons; an increase in oxidation number

oxidising agent

a substance that oxidises another substance; an oxidant; substance that removes electrons from other species; it gets reduced in the process

product

substance resulting from a chemical reaction (right side of the )

reactant

substance participating in a chemical reaction (left side of the )

redox reactions

electron transfer reactions are also known as oxidation-reduction reactions

reducing agent

a substance that reduces another substance; a reductant; substance that donates electrons to other species; it gets oxidised in the process

reductant

a substance that reduces another substance; a reducing agent

reduction

gain of electrons; a decrease in oxidation number