Advertisements
Advertisements
Question
- A to F below relate to the source and extraction of either zinc or aluminium:
- Bauxite
- Coke
- Cryolite
- Froth floatation
- Sodium hydroxide solution
- Zinc blende
- Write down the three letters each from the above list which are relevant to
- Zinc
- Aluminium
- Fill in the blanks using the most appropriate words from A to F.
- The ore from which aluminium is extracted must first be treated with ………………. so that pure aluminium oxide can be obtained.
- Pure aluminium oxide is dissolved in ….. to make a conducting solution.
iii. Write the formula of cryolite.
Advertisements
Solution
a.
i.
1.Zinc
Zinc blende, Froth flotation, Coke
2.Aluminium
Cryolite, Bauxite, Sodium hydroxide solution
b.
ii.
1. The ore from which aluminium is extracted must first be treated with sodium hydroxide solution so that pure aluminium oxide can be obtained.
2. Pure aluminium oxide is dissolved in cryolite to make a conducting solution.
iii.The formula of cryolite is Na3AlF6.
RELATED QUESTIONS
Name the following:
A metal oxide that can be reduced by hydrogen.
Name the compound added to pure alumina to lower the fusion temperature during the electrolytic reduction of alumina.
An element L consists of molecules.
When L is heated with iron metal, it forms a compound FeL. What chemical term would you use to describe the change undergone by L?
How is the following metallic oxide reduced? Write the equation:
Zinc oxide
Explain with reason:
In the electrolytic reduction of alumina, the graphite anode is gradually consumed.
With reference to the reduction of copper (II) oxide , iron (II) oxide, lead (II) oxide and magnesium oxide; place the oxides in order of increasing ease of reduction.[i.e. first write the oxide that is most difficult to reduce and at last, the oxide, that is most easily reduced.]
4 tones of bauxite, 150 Kg of sodium hydroxide and 600 Kg of graphite.
The aluminium compound in bauxite is aluminium oxide and the main impurity is iron (II) oxide. Aluminium is obtained by the electrolysis of aluminium oxide dissolved in cryolite.
(a) When bauxite is treated with sodium hydroxide solution, what happens to:
(i) the aluminium oxide?
(ii) The iron (III) oxide?
Name the following :
A metal oxide that can be reduced by hydrogen
Name two metallic oxides which cannot be reduced by carbon, carbon monoxide or hydrogen.
Give the equation for the reduction of Iron (III) oxide.
