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Question 1

What is metallic bonding in terms of electrostatic attractions?

Answer 1

A metallic bond is the strong electrostatic attraction between positive metal ions and a sea of delocalised electrons.

Question 2

Why do metals conduct electricity, and are malleable?

Answer 2

Metals conduct electricity because the delocalised electrons are free to move throughout the structure.
Metals are malleable because the layers of positive ions slide over each other. This does not affect the bonding in the structure.
This is the same reason as to why metals are ductile.

Question 3

Why do covalent compounds not conduct electricity?(3)

Answer 3

Covalent compounds do not conduct electricity in any state or in solution. This is because the molecules in the compounds do not have any overall charge, so there are no charged particles.
Also the electrons are held tightly in the atoms so they are not able to move from molecule to molecule.

Question 4

Why do ionic compounds conduct electricity when molten or in aqueous solution?(3)

Answer 4

When they are solid the ions are not free to move around because they are held tightly in the lattice.
However when they are molten or if they are dissolved in water they conduct electricity. This is because the ions then become free to move around.

Question 5

Define electrolysis.(2)

Answer 5

Electrolysis is the decomposition(breaking down) of an electrolyte using electricity.

Question 6

State what Cathode, Cation, Anode and Anion are?(3)

Answer 6

The Cathode is the negatively charged electrode and the Anode is the positively charged electrode.
At the Cathode reduction takes place and at the Anode oxidation takes place.
Meanwhile the Cation is a positively charged ion and an Anion is a negatively charged ion.

Question 7

What is an electrolyte?

Answer 7

An electrolyte is a liquid or solution that undergoes electrolysis.

Question 8

What are some common elements used as electrodes?(3)

Answer 8

Carbon, Platinum, Graphite.

Question 9

Describe the electrolysis of Molten Lead(II) Bromide?(3)

Answer 9

Once the lead(II) Bromide melts, there will be a current flowing through it.
There will be bubbling around the anode and a bromine gas will be given off.
At the cathode nothing seems to happen but once the apparatus is lifted metallic lead is found underneath.

Question 10

Explain the electrolysis of Molten Lead(II) Bromide?(3)

Answer 10

PbBr2 contains Pb(2+) ion and 2Br- ions.
The Pb(2+) ion are attracted to the cathode and are discharged to Pb(2+) + 2e- = Pb.
The 2Br(-) ions are attracted to the anode and are discharged to 2Br- = Br2 + 2e-.

Question 11

Explain and describe the electrolysis of Sodium Chloride solution?(4)

Answer 11

NaCl+H2O. Final solution NaOH.
At the Anode there will be mainly 2Cl- = Cl2 + 2e- but also very few OH- produced from the H2O
At the Cathode while Sodium is Na+ because it is more reactive than Hydrogen it is harder to revert it to an ion therefore Hydrogen from the water will go to the Cathode instead.
If universal indicator is present the Cathode will turn blue because of the OH- created from H2O build up around the cathode. At the Anode will be Orange.

Question 12

Explain and describe the electrolysis of Dilute Sulfuric Acid?(3)

Answer 12

(H2)SO4
At the Anode there will be sulphate and hydroxide ions 4OH- = 2H2O + O2 + 4e-
More than twice as much Hydrogen is collected when this experiment is carried out because some oxygen is dissolved in solution.

Question 13

Explain and describe the electrolysis of Copper(II) Sulfate solution?(4)

Answer 13

CuSO4. Final product of non-discharged ions H2SO4.
At the Anode sulphate and hydroxide ions will be attracted but only hydroxide ions will be discharged. 4OH- = 2H2O + O2 + 4e-
At the Cathode copper and hydrogen ions will be attracted but only copper ions will be discharged.
Cu(2+) + 2e- = Cu
Also at the Anode there will bubbles of oxygen and the Cathode will be coated with pink-brown copper.

Question 14

Why can Aluminium ore(Bauxite) be produced at a low temperature and why is this beneficial industrially?(3)

Answer 14

Al2O3 is dissolved in molten cryolite which lowers the melting point of the mixture, therefore it can be electrolysed at a lower temperature. This lowers the cost because reduces electricity input and also reduces risk of melting the steel casing.

Question 15

Describe and explain the production of Aluminium from Aluminium ore(Bauxite)?(4)

Answer 15

At the Cathode Al(3+) + 3e- = Al.
At the Anode 2O(2-)- = O2 + 4e-
Both the Cathode and Anode are made from Graphite.
The Anode is dipped into the solution and needs to be replaced frequently because the oxygen produced there reacts to form Carbon Dioxide and wears it down.

Question 16

What are some properties and uses of of Aluminium?(2)

Answer 16

Malleable, lightweight.
Kitchen foil, utensils.

Question 17

Describe and explain the electrolysis of Brine(Sodium Chloride solution)?(5)

Answer 17

The apparatus that it takes place in is called the membrane cell.
At the Anode Chlorine is produced and collected at the top of the membrane cell.
At the Cathode Hydrogen, which is also collected at the top of the cell, and Sodium Hydroxide, which is collected on the right hand side of the cell, are created.
The point of the whole membrane cell is to stop Chlorine and Sodium coming into contact with each other.