CHEMISTRY.. SEPERATING TECHINQUES quiz on TUESDAY.. help

[wanabeastarstudent]

  hey.. well i got a quiz on tuesday on thse things from the past year but i didnt study last year so can u help me wiv these topic n post websites plz?

*state of matter
*seperating techniques and mixtures
*atomic structure
*bonding (metallic,covalent,ironic and macromolecular)

thanks so much
and im doing extraction of iron (Fe), aluminuim and zinc do u have any websites? cuz i started skwl late so i missed out thanks u guys are great   please help

[The Golden Girl =D]

https://studentforums.biz/references-and-resources/ultimate-resource-guide-for-igcse/
Check this out :

https://studentforums.biz/sciences/chemistry-p3-762010/

[The Golden Girl =D]

this as well

https://studentforums.biz/sciences/chemistry-p6-185010/

[wanabeastarstudent]

thanks <3 im confused can someone explain this please??

 Extraction of metal (Aliminuim)
*low density ........ airoplane......body
*resist corrosion......>window+door frames
*reflection of heat......> food.........> container rust
*conductor or heat.....> kitchen wear
*conductor of electricity........> over head cables

please explain and can u give me any info about this topic im confused  ugh.. n i need to know about zinc and copper aswel... hm.. thanks a bunch
is al high density or low? i dont even know wat it means

[Vin]

Alright I shall start from scratch, to avoid confusion.

Extraction of Aluminium.

Aluminium ore --> Bauxite (Aluminium oxide/Alumina Al₂O₃)
Separation method --> Electrolysis



[If image too small - Right-click > View image]

Electrlysis is carried out in this, huge steel tank.
The walls are lined with Carbon which acts as the Cathode (-)
Huge blocks of carbon hang in the middle of the tank which act as the anode. (+)


Aluminium oxide/alumina is insoluble and it melts at 2045 *C, which is practically impossible to maintain that temperature in the tank environment. Therefore aluminium oxide is dissolved in molten Cryolite (sodium aluminium fluoride) which has a lower melting point.

Once this aluminium oxide dissolves, the aluminium ions and oxide ions are free to move. They move to the electrode of opposite charge.

At Cathode.
Aluminium ions gain electrons. (Reduction)

4Al³⁺  +  12e-  ----> 4Al

At anode
Oxygen ions lose electrons. (Oxidation)

6O^2- ----> 3O₂  + 12 e-

This oxygen bubbles off as carbon dioxide as the anode itself is made of carbon. So these blocks are eaten away and eventually should be replaced.

Overall reaction

2Al₂O₃ ---> 4Al + 3O₂

Properties of Aluminium.
Aluminium is a bluish-silver, shiny metal.

It has low density - it is very light in weight

Good conductor of heat and electricity

Malleable (can be bent easily) and ductile (can be drawn into wires very easily)

It is strong and highly uncreative (Aluminium has the tendency to form a thin coating of Al2O3 over its surface when exposed to air, it never gets 'rust') and is very light. This is very useful for manufacturing of aircraft (light and strong) and food containers (because it is highly uncreative and does not corrode)

Reflection of heat -> It is a shiny metal.

[Vin]

Thank you GG for the links.

Zinc, copper and iron coming up shorty.

[Vin]

Extraction of Zinc.

Zinc ore ---> zinc blende (zinc sulfide - ZnS)

First, it is roasted in air to give zinc oxide:

2ZnS + 3O₂ ---> 2ZnO + 2SO₂


Then the oxide is reduced in one of the following ways:

Method 1. Using carbon monoxide:

ZnO  +  CO --> Zn  +  CO₂

The final mixture contains zinc and a slag of impurities. The zinc is separated from it by fractional distillation.

Method 2. Electrolysis

For this, zinc oxide is dissloved in sufuric acid to give zinc sulfate (salt) and water [Acid + Base -> Salt and Water]

Why this is done? For electrolysis, the general principle is the electrolyte (the solution in container) has to conduct electricity - so for metals or metal oxides it has to either be in molten form or their salt solution. Zinc oxide is a (basic) oxide and is insoluble in water and the melting point is very high. So the salt solution is obtained in order to carry put the electrolysis. So, not necessarily sulfuric acid must be used, any acid for that matter.

At cathode:

Zn²⁺  +  2e- ---> Zn (s)

This zinc is scraped off the cathode. This method is preferable as it gives zinc of very high purity.

[Vin]

Extraction of Copper.

Copper ore ---> malachite (Copper (II) carbonate - CuCO₃)

The reaction takes place in two stages :

Stage 1 - The malachite decomposes :

CuCO₃ (s) --->  CuO (s)  +  CO₂ (g)

Stage 2 - The copper (II) oxide is reduced by carbon :

2CuO (s)  +  C (s) --->  2Cu (s) +  CO₂(g)


This copper is then purified by electrolysis.

[Vin]

For extraction of iron, I shall post a picture from my textbook - explains it really well, after my scanner or even the webcam decide to function.

OK not working out really well so here are the notes :

Extraction of iron.

Iron ore ---> haematite (Iron (II) Oxide - Fe₂O₃)

   
[If image too small - Right-click > View image]


yeah so as you can see the extraction of Fe takes place in a blast furnace.

Raw materials used to put at the top.
>Iron ore (Fe₂O₃)
>Coke (Main source for Carbon needed for the reduction process)
>Limestone (needed to remove the impurities in the form of 'slag')

Steps in which the extraction is conducted :

1. Iron ore, coke and limestone are fed into the top of the blast furnace.

2. Hot air blasted up the furnace from the bottom.

3. Oxygen from the sir reacts with coke to from carbon dioxide.
C (s) + O₂ (g) ---> CO₂ (g)

4.Carbon dioxide reacts with more coke to form carbon monoxide
CO₂ (g)  +  C (s) ---> 2CO (g)

5.Carbon monoxide is a reducing agent.
Iron (II) oxide is reduced to iron :

Fe₂O₃ (s) +  3CO (g) ---> 2Fe (l)  +  3CO₂ (g)

6. Dense molten iron runs to the bottom of the furnace and is run off. There are many impurities in iron ore. The limestone helps to remove these shown in steps 7 and 8.

7. Limestone is broken down by heat to calcium oxide :
CaCO₃ (s) --->  CaO (s)  +  CO₂ (g)

8. Calcium oxide reacts with impurities like sand (silicon dioxide) to form a liquid called 'slag':
CaO (s)  +  SiO₂ (g)  --->  CaSiO₃  (l)
                                          (calcium silicate)

the liquid slag falls to the bottom of the furnace and is tapped off.

The overall reaction :

2Fe₂O₃ (s)  +  3C  --->  4Fe  +  3CO₂

Reduction reaction stages :

Stage 1 - The coke reacts with oxygen blasted into the furnace :
C (s)  +  O2 (g) --->  CO2 (g)

Stage 2 - The carbon dioxide is reduced by unreacted coke to form carbon monoxide :
CO2 (g)  +  C (s)  --->  2CO (g)

Stage 3 - The iron (iii) oxide is reduced by the carbon monoxide to iron :
Fe₂O₃ (s)  +  3CO (g) --->  2Fe (s) + 3CO2 (g)

[Vin]

hey.. well i got a quiz on tuesday on thse things from the past year but i didnt study last year so can u help me wiv these topic n post websites plz?

*state of matter
*seperating techniques and mixtures
*atomic structure
*bonding (metallic,covalent,ironic and macromolecular)

thanks so much
and im doing extraction of iron (Fe), aluminuim and zinc do u have any websites? cuz i started skwl late so i missed out thanks u guys are great  please help

OK, here are a couple of ppts. The rest I'll try to type out notes after a while.

[Vin]

Some notes which might help.

[wanabeastarstudent]

SEPERATION OF SUBSTANCESS isnt working?? why
but the rest is amazing plz see if u can do anything about seperation of substances and is there any questions on the past papers that i can do relating to the things i will get a quiz on plz past paper 3 and 6 thanks

[The Golden Girl =D]

SEPERATION OF SUBSTANCESS isnt working?? why
but the rest is amazing plz see if u can do anything about seperation of substances and is there any questions on the past papers that i can do relating to the things i will get a quiz on plz past paper 3 and 6 thanks

look at the pps i gave u for chem ppr 6 and check the first question from year 2005 and up they're solved , it'll help u out a lilttle bit

as for anything else i suggest u revise chromatography June 2010 chem ppr 6 there is a good Q on chromatography ...Well i'll try to help u tmrrw (tho i'll be comin late bas iA i'll try to help ya out )

[wanabeastarstudent]

:O so chromotography is involved??

[Amii]

For extraction

ppr 3  

m/j/02 - 1a-1d
m/j/03 - 1
m/j/05 - 6a
o/n/05 - 5b
m/j/06 - 1
m/j/07 - 6

bonding-

ppr 3

m/j/04 - 1b-1c
o/n/04 - 5b
m/j/05 - 5b iii
o/n/05 - 1a
m/j/06 - 4
m/j/07 - 2
m/j/07 - 4a - 4c
o/n/08 - 2
o/n/09 - 5

chromatography/separating techniques-

ppr 3

m/j/05 - 5ai - 5aiii
o/n/07 - 1,3a,bi-bii

ppr 6

m/j/02 - 2
o/n/03 - 1
o/n/04 - 7
m/j/05 - 6
o/n/05 - 3
o/n/06 - 5
m/j/09 - 1,3
o/n/09 - 7
m/j/07 - 1,3
o/n/08 - 1
m/j/09 - 1

states of matter-

ppr 3

o/n/05 - 2a

atomic structure-

ppr 3
m/j/08- 2

hey wanna i will give u the 90's ppr tom - have a test tom - so cant give dose now 
Take care n keep smiling