Chapter 5 Galvanic cells as a source of energy

Question 1

Accumulator

Answer 1

A secondary, or rechargeable, electrochemical cell

Question 2

Alkaline Cell

Answer 2

A commercial electrochemical cell with an alkaline electrolyte that is a moist paste rather than a solution

Question 3

Anode

Answer 3

An electrode at which an oxidation reaction occurs (opposite of RED CAT)

Question 4

Battery

Answer 4

A combination of cells connected in series

Question 5

Battery life

Answer 5

A measure of the performance of a battery. It can be the time the battery operates in a device following a full charge or the number of charge-discharge cycles before the battery becomes unusable.

Question 6

Cathode

Answer 6

An electrode at which a reduction reaction occurs (RED CAT)

Question 7

Electrochemical cell

Answer 7

A device that converts chemical energy into electrical energy or vice versa

Question 8

Electrochemical series

Answer 8

A list of half-equations, written as reduction reactions, arranged in order so that the strongest oxidising agents are at the top, left-hand-side of the list.

Question 9

Electrode

Answer 9

A (usually) solid conductor in a half-cell at which oxidation or reduction reactions occur

Question 10

Electrolyte

Answer 10

A chemical substance which conducts electric current as a result of dissociation into positively and negatively charged ions, which migrate to the negative and positive terminals of the electric circuit.

Question 11

Electromotive force

Answer 11

The ‘electrical pressure’ between two points in a circuit, such as the electrodes of an electrochemical cell; a measure of the energy given to electrons in a circuit.

Question 12

Electronegative

Answer 12

A measure of the ability of an atom of an element to attract electrons.

Question 13

External circuit

Answer 13

The section of an electrochemical cell in which electrons move. This section of the circuit will include the wires attached to the electrodes.

Question 14

Galvanic cell/Voltaic cell

Answer 14

A device which converts chemical into electrical energy.

Question 15

Galvanometer

Answer 15

An instrument for detecting electric current

Question 16

Half cell

Answer 16

Half an electrochemical cell which contains the oxidant and its conjugate reductant. When two half-cells are combined, a galvanic cell is formed.

Question 17

Half equation

Answer 17

A balanced chemical equation which shows the loss or gain of electrons by a species during oxidation or reduction.

Question 18

Inert electrode

Answer 18

An electrode which is not consumed by the reaction occurring at the electrode. The electrode serves only as a conductor of electrons. Precious metals and carbon are typically used as inert electrodes.

Question 19

Internal circuit

Answer 19

The section of an electrochemical cell in which ions move eg solutions and salt bridge.

Question 20

Lithium-ion cell

Answer 20

A galvanic cell which generates electricity from the oxidation of lithium embedded in the lattice structure of a graphite rod and the reduction of a metal oxide. The reduction product combines with the lithium ions.

Question 21

Non-rechargeable cell

Answer 21

A primary galvanic cell

Question 22

Volt

Answer 22

The unit of potential difference. One volt is defined as one joule per coulomb of charge.

Question 23

Voltmeter

Answer 23

An instrument for measuring electrical potential difference between two points in an electrical circuit.