Redox glossary

Question 1

redox reaction

Answer 1

A chemical reaction that involves the transfer of electrons

Question 2

reduction

Answer 2

the oxidation number decreased as it gains electrons

Question 3

oxidation

Answer 3

the oxidation number increases as it gains electrons

Question 4

oxidising agent/oxidant

Answer 4

species that becomes reduced and causes other species to become oxidised

Question 5

reducing agent/reductant

Answer 5

species that becomes oxidised and causes other species to become reduced

Question 6

oxidation numbers

Answer 6

the number assigned to an element, representing the number of electrons gained or lost by an atom of that element to form a chemical bond

Question 6

conjugate redox pairs

Answer 6

the electron donor (reducing agent) and its corresponding electron acceptor (oxidising agent)

Question 7

electrochemical series

Answer 7

arrangement of chemical series in order of their reducing and oxidising strengths

Question 8

redox half equation

Answer 8

one of two equations (oxidation and reduction) that describe one half of the redox reaction

Question 9

galvanic cell

Answer 9

an electrochemical cell that converts chemical energy to electrical energy through spontaneous reactions

Question 10

anode

Answer 10

negatively charged electrode in galvanic cells. Oxidation always occurs at the anode

Question 11

cathode

Answer 11

positively charged electrode in galvanic cells. Reduction always occurs at the cathode

Question 12

salt bridge

Answer 12

The connection that allows the flow of ions between two half-cells to maintain the
electrical neutrality of the cell

Question 13

electrode

Answer 13

An electrical conductor that is either unreactive or involved in the reaction

Question 14

standard half-cell

Answer 14

consisting of both members of the conjugate redox pair and an electrode at standard conditions

Question 15

standardised half-cell

Answer 15

hydrogen and hydrochloric acid standard half-cell

Question 16

standard electrode potential

Answer 16

The potential of half reaction (reduction) given in volts, relative to standard hydrogen half cells

Question 17

spontaneous reaction

Answer 17

A reaction that occurs in a set of conditions without being forced to/without external energy source

Question 18

direct redox reaction

Answer 18

A reaction where the chemical species react together in the same vessels

Question 19

indirect redox reaction

Answer 19

A reaction where the chemical species react together in separate vessels

Question 20

fuel cell

Answer 20

An electrochemical cell that continuously converts chemical energy into electrical energy by a redox reaction

Question 21

porous electrode

Answer 21

A material with many holes (pores) which is used in a fuel cell to maximise the ability for gaseous