Chapter 12 - Redox

Question 1

Reduction

Answer 1

The gain of electrons. For example:
Fe²+ (aq) + 2e- → Fe (s)

Question 2

Oxidation

Answer 2

The loss of electrons. For example:
Fe (s) → Fe²+ (aq) + 2e-

Question 3

Anode

Answer 3

The electrode where oxidation occurs (generally negative, but not always!) Note: electrons flow from anode to cathode.

Question 4

Battery

Answer 4

A series of galvanic cells connected together, used as a portable power source.

Question 5

Half Equation

Answer 5

An equation that describes one half of a redox reaction (either reduction or oxidation). For example: O₂ + 4e- → 2O²-

Question 6

Redox Reaction

Answer 6

A type of chemical reaction where reduction and oxidation are both taking place. For example: 2Mg + O₂ → 2MgO

Question 7

Oxidising Agent/Oxidant

Answer 7

The substance that gets reduced (i.e. gains electrons) in a redox reaction. Note: will be an ion.

Question 8

Reducing Agent/Reductant

Answer 8

The substance that gets oxidised (i.e. loses electrons) in a redox reaction.

Question 9

Metal Displacement Reaction

Answer 9

A chemical reaction in which a more reactive metal displaces (swaps places with) a less reactive metal in solution. General formula: AB + C → CB + A (where B is a spectator ion).

Question 10

Daniell Cell

Answer 10

The first mass produced galvanic cell, using zinc as a reducing agent and CuSO₄ as an oxidising agent.

Question 11

Galvanic/Voltaic Cell

Answer 11

An electrochemical cell that converts the chemical energy of redox reactions into electrical energy. Consists of an anode, cathode and salt bridge.

Question 12

Cathode

Answer 12

The electrode where reduction occurs (generally positive, but not always!). Note: electrons flow from anode to cathode.

Question 13

Half Cell

Answer 13

One of the two electrodes in a galvanic cell; either the anode or the cathode.

Question 14

Conjugate Oxidising Agent

Answer 14

The product formed from a reducing agent. (i.e. the product of oxidation).

Question 15

Conjugate Reducing Agent

Answer 15

The product formed from an oxidising agent (i.e. the product of reduction).

Question 16

Salt Bridge

Answer 16

The connection between the anode and cathode in a galvanic cell, which contains a solution of KNO₃. Balances the charges of the two half cells and completes the circuit.

Question 17

Electrode

Answer 17

The solid metal conductor in a half cell, such as a metal rod. (usually the reducing agent, but not always).

Question 18

Electrolyte

Answer 18

The solution in which electricity is conducted in a half cell. (usually the oxidising agent, but not always).