Electrolysis

Question 1

conduct electricity when molten or aqueous.

Answer 1

Ionic compounds

Question 2

When an electric current passes through such compounds, the compounds are decomposed in a chemical reaction. This
is known as

Answer 2

electrolysis

Question 3

The ionic compound is called an

Answer 3

electrolyte

Question 4

*The electrode attached to the positive terminal of the cell.
*Anions are attracted to it.

Answer 4

Anode

Question 5

*The electrode attached to the negative terminal of the cell.
*Cations are attracted to it.

Answer 5

Cathode

Question 6

are usually made of carbon or platinum, as they are
unreactive or inert.

Answer 6

Electrodes

Question 7

take electrons from the cathode to become lead
atoms (reduction).

Answer 7

lead ions (At the cathode)

Question 8

s donate electrons to the anode to become
bromide molecules (oxidation).

Answer 8

At the anode
The bromide ions

Question 9

are attracted to the anode

Answer 9

Bromide ions

Question 10

are attracted to the cathode

Answer 10

Lead ions

Question 11

move near to cathode

Answer 11

Lead ions

Question 12

move near to anode

Answer 12

Bromide ions

Question 13

take electrons from the electrode to become
hydrogen atoms (reduction).

Answer 13

At the cathode
The hydrogen ions

Question 14

There are two anions in the electrolyte:

Answer 14

hydroxide and chloride ions

Question 15

from the electrolyte are discharged if they are chloride, bromide or iodide ions. For sulphates and nitrates, oxygen from water is discharged

Answer 15

Negative ions

Question 16

from the electrolyte that are below Ni2+(aq) in the electrochemical (or reactivity) series are discharged at the
negative cathode.

Answer 16

Positive ions

Question 17

If the positive ions are those of reactive metals above Ni2+(aq)
(e.g.. Na+, K+ and Ca2+), hydrogen gas from water is

Answer 17

discharged

Question 18

Anions

Answer 18

K+ (aq)
Na+ (aq)
Ca2+ (aq)
Mg2+ (aq)
Zn2+ (aq)
Fe2+ (aq)
Pb2+ (aq)
H+ (aq)
Cu2+ (aq)
Ag+ (aq)

Question 19

Cations

Answer 19

SO4
2-
(aq)
NO3
-
(aq)
Cl -
(aq)
Br -
(aq)
I -
(aq)
OH -
(aq)
SO4
2-
(aq)

Question 20

The decomposition of a substance by electricity is
called

Answer 20

electrolysis

Question 21

is an ionic compound, in the molten or aqueous state, that conducts electricity and is decomposed by the current

Answer 21

electrolyte

Question 22

The rods through which the direct current enters and
leaves the cell are known as

Answer 22

electrodes

Question 23

are usually inert.

Answer 23

Electrodes

Question 24

is the electrode which is connected to the positive terminal of a cell. Anions are attracted to it. Oxidation occurs at the anode

Answer 24

anode

Question 25

is the electrode connected to the negative terminal of the cell. Cations are attracted to the cathode. Reduction occurs at this electrode.

Answer 25

cathode

Question 26

When a molten electrolyte is electrolysed,

Answer 26

*a metal (from the positive ions) is discharged at the cathode.
*a non-metal (from the negative ions) is discharged at the anode.

Question 27

When a aqueous electrolyte is electrolysed

Answer 27

*the products come from either the electrolyte or water present.
*The product at the cathode is a metal or hydrogen gas.
*The product at the anode is a non-metal

Question 28

are not discharged at the cathode. Instead, hydrogen from water is evolved

Answer 28

Reactive metals

Question 29

are not discharged at the anode. Instead, oxygen from water is produced.

Answer 29

Sulphate and nitrate ions