The students are expected know about Useful Products from Metal Ores. This is what is mentioned in the specification.
When I cut and paste from my work, some of the work do not come as required but it comes up nicely in a CD, so when you request a CD of your chosen piece of work, it will be included. They can be printed out, it saves you HOURS OF COPYING NOTES. I know some students when they go for private tuition, what they do? They just copy and copy, no more then come home again copy. Here I give everything written up for you. All you got to do is to study and write them in the exam. My work is exam oriented that is the difference.
Let me explain the extraction of Iron and Aluminium.
Extraction Iron [Work Modified on 22/9/07]
In some countries including England, gold is found as a pure metal but Iron is not found as a pure metal, it is found as oxides or sulphides. The source of any metal is called an Ore, and there are three Ores of iron, Fe 2 O 3 is the HAEMATITE, Fe 3 O 4 is the MAGNETITE, FeS is the IRON PYRITES also called IRON SULPHIDES.
How Iron is extracted from the Ores .
If oxygen is removed from the oxides of iron, then Iron can be obtained. When iron sulphides are used, first it is roasted in the air and converted into oxides of iron.
Q: What type reaction is called the removal of oxygen from a compound, Oxidation or reduction ?
[A]: It is called a reduction.
Let me give some additional information. Industrially a process called Blast Furnace Process manufactures iron. The principle of removal of oxygen is by reduction, which is done in several stages. Remember removal of oxygen from any compound is called a reduction. For GCSE purpose, the students are expected to know about this process, just the main stages of production of iron.
NOTE : Usually the questions are based on the source, raw materials, type of reaction and the source of energy for the process. They are not asking many lines of explanation but a few words such as follows.
Ores of iron : Fe 2 O 3 is the HAEMATITE, Fe 3 O 4 is the MAGNETITE, FeS is the IRON PYRITES also called IRON SULPHIDES.
Raw materials : Iron ore, coke and limestones.
Source of energy : Heat energy.
Type of reaction : Reduction.
What is the reducing agent : Carbon monoxide.
Impurities : Slag, which contains calcium silicate.
Extraction of Iron by Blast Furnace Process.
Iron ore is mixed with limestones and coke and filled into a furnace called blast furnace, which is a very tall tower. It is specially designed for the purpose with heat resisting bricks and steel plates. The mixture is heated and hot air containing Carbon dioxide, which is blown through the reacting mixture.
Carbon (s) + Oxygen (g) ---heated--- à Carbon dioxide (g)
C(s) + O 2 (g) ---- à CO 2 (g)
Note: The state symbols are s = soild, g = gas.
As carbon dioxide goes through the heated mixture of iron ore and lime stones and coke it becomes carbon monoxide by reacting with coke in the mixture. Carbon monoxide reacts with the oxides of iron and REDUCE OXIDES OF IRON TO MOLTEN IRON.
Iron oxide (s) + carbon monoxide ---heated- à Iron (s) + Carbon monoxide (g) [This is the word equation]
Fe 2 O 3 (s) + 3CO(g) ---- à 2Fe(s) + 3CO 2 (g)
The molten iron and the impurities are removed separately from the bottom of the blast furnace.
Q: What is molten means?
Ans: Melted without water. You can have molten sugar when you make cameral sugar syrup.
Have you not heard molten lava from volcanoes? It has liquid rocks, yes these rocks flowing like red water. How many times you have seen these things in your films and cartoons? You can sometimes link your knowledge from other resources to classroom work. Fuji volcano eruptions are sometimes spectacular to see.
I am sure you have seen videos or films in the classroom about iron industry and production of steel. How steel is produced, what is stainless steel and similar industries.
NOTE : If you know extraction of iron, it will be good enough for the exams but they also can ask several other questions related to the process.
THE FOLLOWING ARE POSSIBLE IN EXAMS :
2.What is the purpose of the limestone?
3.What are the uses of iron and slag?
4.Is the process is economical than electrolysis extraction of metals. 5.They might give a diagram of blast furnace and ask to label it or draw a blast furnace. I am sure you don’t have to draw it.
6. Balanced equations with correct symbols including the state symbols must be known. [DIAGRAM of Blast Furnace is found in my book]
What is coke: Coke is smokeless coal it is nothing but carbon it is obtained by heating coal until no more smoke is given out.
NOTE: You can make a similar type of smokeless charcoal from COCONUT shells. I saw this in Sri Lanka how the people use coconut charcoal to boil little boilers and used also in ironing. You can also produce smokeless wood charcoal by burning logs of wood. You burn the logs in a restricted supply of air and put down the fire by pouring water on it when it stopped smoking. This charcoal can be re-lighted and usually use in BBQ. This is big business in summer time.
The reason I give this information is to widen the student's knowledge to outside world for day today applications. This makes them to understand the subject better, make them physiologically feel that CHE MISTRY is not a MYSTRY subject.
Purpose of the Lime stones for the blast furnace: Lime stone is calcium carbonate when it is heated it decomposes into carbon dioxide and calcium oxide.
CaCO 3 (s) ------ > CaO(s) + CO 2 (g)
Iron ores are contaminated with impurities such as sand, which becomes Silicon oxide or Silica (sand) when they are heated up along with the iron ore. Silicon is a non-metal and the oxides of non metals are acidic. Calcium oxide reacts with the acidic impurities (silicon oxide) to give calcium silicate.
CaO(s) + SiO 2 (s) ----- > CaSiO 3 (l)
Calcium oxide sand (Silicon oxide ) Calcium silicate (slag).
What are the uses of slag.
Slag looks like small stones or stone chipping , it is mixed with Bitumen and use for road surfacing. It is also mixed with concrete to lay foundations. Slag is a rubbish, Bitumen is also a rubbish but when mixed them together we get the most useful product to lay as carpets on roads. Any road that is covered with this carpet is made by mixing these two rubbish products. This is application of classroom chemistry and knowledge for day to day life.
Economy of the process.
The process is cheaper than electrolytic extraction of metals because coal and coke are cheaper than electricity.
Blast Furnace diagram is attached. Study the diagram carefully and redraw at your own time and try and remember it roughly.
[The diagram CAN JAM THE TELEPHONE LINE] The diagram is available in your CD.
HENCE I AM NOT SENDING THE DIAGRAM THIS WAY. IT IS FOUND IN MY BOOK IN THE SIMPLEST WAY]. One can buy the book at a student’s discount price.
If anything in the book needs further explanation, it is provided with FREE of charge. Would you like to get help on the INTERNET? So why not email today.
Unlike in other text books, I will tell the students in a way that they can understand the work, take the fear out of the subject, make it a pleasant subject to study, an enjoyable subject to study. This is my theory and in the past it has worked wonders. Take Internet Tuition today.