6.1-6.4: Electrolysis

Electrode

________ is a rod of metal or graphite through which an electric current flows into or out of an electrolyte.

Negative bromide ions

________ move to the positive electrode (anode) and each loses one electron to form bromine molecules.

Copper

________ is used extensively in electrical wiring as it is an excellent conductor and is malleable and easy to work with.

Molecular substances

________ are non conductors because they contain no free electrons or charger particles that can flow through them.

aqueous solution

The electrolyte is a(n) ________ of a soluble salt of the pure metal at the anode.

Anion

________ is a negatively charged ion which is attracted to the anode.

rubber

Most insulators are solids of plastic, ________ or ceramic.

cathode

The ________ is the object to be electroplated.

Ceramics

________ are used in very high voltage lines where contact between the power line and the metal of the pylon would be dangerous.

Hydrogen

________ is used to make margarine.

chlorine

When electrolysed it produces ________ and hydrogen at the electrodes leaving behind sodium hydroxide solution.

aluminium

Although not as good a conductor as copper, ________ is less dense and cheaper than copper.

5 6 volts

The cell operates at ________ and with a current of 100, 000 amps.

Electrolyte

________ is the ionic compound in molten or dissolved solution that conducts the electricity.

Cation

________ is a positively charged ion which is attracted to the cathode.

Anode

________ is the positive electrode of an electrolysis cell.

Plastics

________ are used as insulators and are placed around electrical wiring and for some tool and machine handles.

Earths Crust

The ________ contains metals and metal compounds such as gold, iron oxide and aluminium oxide.

Brine

________ is a concentrated Solution of Sodium Chloride or common salt.

Electrolysis

________ is the break down of an ionic compound when in molten or in aqueous form by the passage of electricity.

bauxite

The ________ is first purified to produce aluminium oxide Al2O3.

Ionic substances

________ dont conduct when solid but do conduct when melted or dissolved.

Sodium hydroxide

________ is used to make soap and detergents.

Positive lead ions

________ move to the negative electrode (cathode) and gain electrons to form a grey lead metal which deposits on the surface of the electrode.

steel core

The ________ provides extra strength and prevents the cable from breaking under its own weight.

halide solution

If a dilute ________ is being electrolysed, oxygen is formed.

Insulators

________ resist the flow of electricity and do not conduct.

Metals

________ which lie above carbon have to be extracted by electrolysis as they are too reactive to economically be extracted by displacement.

sodium

The electrolyte is concentrated ________ chloride which contains the following ions: Na+, H+, Cl- and OH-

Anode Negative

Positive is ________ is Cathode.

halide ions

If no ________ are present, then OH- is discharged at the anode, gains electrons and forms oxygen gas.

Non metal ions

________ (other than hydrogen) are attracted to the positive electrode.

Aluminium oxide

________ has a very high melting point so it is first dissolved in molten cryolite producing an electrolyte with a lower melting point, as well as a better conductor of electricity than molten aluminium oxide.

Covalent compounds

________ can not conduct electricity hence they do not undergo electrolysis.

Ionic compounds

________ in the solid state can not conduct electricity either since they have no free ions or electrons that can move and carry charge.

metal ions

Positively charged H+ and ________ are attracted to the negative electrode but only one will gain electrons.

Cathode

________ is the negative electrode of an electrolysis cell.

Aluminium

________ is used in overhead cables which are reinforced with a steel core.

Chlorine

________ is used to make bleach.

remember

P A N I C

Material obtained is

Aluminum ore Bauxite

2NaCl (aq) + 2H20 (l)

> 2NaOH (aq) + Cl2 (g) + H2 (g)

The electrolyte is concentrated sodium chloride which contains the following ions

Na+, H+, Cl- and OH-