Preparing For Chemistry 5070 P1 / P2

[multixamza01]

Back to Topic .

Acid Rain :
Sulfur dioxide and Oxides of Nitrogen in the air mix with rainwater to form sulfuric acid and nitric acid respectively . This acid mixture is dilute in nature and so doesn't show any great harm but has many affects :

Limestone (Calcium Carbonate ) is an important component of cement and dissolves in acid rain (acid-carbonate reaction). So buildings and statues corrode .
Galvanished metals corrode more easily .
Fish cannot survive in acidic rainwater .
K+ and Ca+ that are important nutrients for plants get dissolved in acid rain water and get washed away .

Now next would be Ozone Depletion !

 

[multixamza01]

Okay , looks like no one is present in class today

So Chlorofluorocarbons are released in the atmosphere by Aerosol sprays , bla bla bla . They react with the Ozone layer in the atmosphere and dissolve it . This layer protects the Earth from ultraviolet rays from the Sun . A hole has been formed in the layer over Antarctica and is growing , melting the Continent .

So now we move onto Greenhouse Effect . I'll make this quick :

The greenhouse gases make up a layer in the atmosphere. When UV light passes through this layer of gases , it's wavelength increases . When in comes in contact with the surface of earth , some of it is absorbed but a slight amount is reflected . The long waves are unable to escape the greenhouse layer and are trapped . The billion of these trapped UV rays plus the absorbed ones contribute to increase the temperature of our atmosphere .

Now someone please explain Water Pollution .

 

[farahdar]

Is water pollution related with the deposition of sewage and industrial waste ect or the seepage of fertilizers into the rivers leading to eutrophication?

 

[scouserlfc]

Is water pollution related with the deposition of sewage and industrial waste ect or the seepage of fertilizers into the rivers leading to eutrophication?

Yeah it consists of this but there are more things than that it is based upon these facts !
1.sewage deposition ----> water diseases if drunk by humans and oxygen lessens for water organisms
2.Fertilizers ( Leading to Eutrophication )
3.Heavy metals like mercury from industries ----> poisoning occurs if they increase in conc in ur body normally become conc. as they move through the food chain
4.Oil spills,mud,twigs ............... ----> makes water and undrinkable and filthy plus oil kills aquatic organisms !

Now some one purify this water and do fractional distillation of air ! And i guess everyone knows abt where different air pollutants come from !

 

[farahdar]

Yeah, of course..fractional distillation of air..compress and liquify..then cool liquid air..oxygen -183, nitrogen -196, argon -183 i think

 

[farahdar]

Yeah, of course..fractional distillation of air..compress and liquify..then cool liquid air..oxygen -183, nitrogen -196, argon -183 i think

argon -186

 

[farahdar]

argon -186

Sorry forgot to mention..after cooling..liquid air is heated..the gas with the lowest boiling point distils over first..and that with the highest at the end..thus air is separated into its components..

 

[multixamza01]

Water purification has these three steps .
(i)filtration to remove solids
(ii) use of carbon to remove tastes and odors
(iii) chlorination to disinfect the water
seawater can be converted into drinkable water by desalination

Carbon Cycle is left , but we did that in Bio !

But for the computer students , i'll just summarize it :
Carbondioxide ---> Plants ---> i)Atmosphere(Decay) ii) Animals (Feeding) ----> Death and Decay .

In words , the plants absorb carbondioxide to carryout photosynthesis . They release some of it at night . When plants die theor bodies are decayed by micro-organisms and the stored carbon is released. When animals feed on living plants they consume the carbon content. So when animals die they're bodies also release carbon dioxide after decay . This cyclic flow is known as the carbon cycle .

Now Air and Water is complete .
Moving On to Metals .

 

[multixamza01]

First i think we have to know the Reactivity Series :

Potassium
Sodium
Calcium
Magnesium
Aluminium
Zinc
Iron
Tin
Lead
Hydrogen
Copper
Mercury
Silver
Gold

There are a number of mnemonics to memorize this Series . I'll post the way i learnt it (it is based upon the Symbols of the elements , not the names )

Kamal (K)
Nasir (Na)
Ka (Ca)
Mamon (Mg)
Ali (Al)
Zafar (Zn)
Fashion (Fe)
Show (Sn)
Pe (Pb)
Hara (H)
Kyun (Cu)
Harra (H)
Ajj (Ag)
Aoo (Au)

Not perfect , but works . But you can learn it anyway you like , what matters is that you know it .

So i guess , this covers a major part of the chapter .
The higher metals can displace the lower metals from the latter's compounds but vice versa is not normally possible .

The only exception is when a metal is heated , it is able to displace the metal immediately above it but not any further as the difference in reactivity becomes too great .

Carry on from here .

 

[UziB]

Now on to the reactivity series of NON-METALS.
1) Fluorine
2) Sulfate
3) Nitrate
4) Chlorine
5) Bromine
6) Iodine
7) Hydroxyl.

Same reaction mechanism is followed as was done by the reactivity series of metals i.e more reactive displaces less reactive.

 

[UziB]

Major reactions in the chapter of METALS/NON-METALS are as follows:
1) Reaction of metal + acid (only possible for those metals above hydrogen)
2) Reaction of metal + cold water (only possible from potassium to calcium)
3) Reaction of metal + steam (only possible from magnesium to lead)
4) Displacement of metals from their oxides by other metals (metals can only displace those metals from their oxides which are lower than them in the reactivity series e.g Hydrogen will be able to displace Copper from CuO)
5) Displacement of metals from their aqueous solutions by other metals (same mechanism is followed as stated above)
6) Displacement of metals from their oxides by C/CO (products formed in this reaction are always Carbon Dioxide and the metal displaced)
7) Decomposition of metal carbonates (products formed are always an oxide of the decomposed metal and carbon dioxide)
8) Decomposition of metal nitrates (products formed are always an oxide of the decomposed metal, nitrogen dioxide and oxygen)

That pretty much sums it all up

 

[osama]

you can learn that way also

potassium
sodium
calcium
magnesium
aluminium
zinc
iron
lead
hydrogen
copper
mercury
silver
platinum
__________

please
send
cats
monkeys
and
zebras
in
large
high
cages
make
sure
padlocked

 

[ayeshaK]

http://www.scribd.com/collections/3026541/GCE-O-Level-Chemistry-Pure
CHEMISTRY QUICK REVISION NOTES

 

[khalil]

Colors , and flames of different componds please .

 

[farahdar]

Colors , and flames of different componds please .

Potassium - lilac flame, Sodium - yellow flame

 

[UziB]

Colors , and flames of different componds please .

Group 1 Oxides/Carbonates = White​

Solid Copper = Reddish/pink​

Copper Oxide = Black powder​

Copper Carbonate = Green solid​

Copper(II) Sulfate = Blue Solution​

Hydrated Copper(II) Sulfate = Blue crystals​

Anhydrous Copper(II) Sulfate = White crystals​

Copper(I) Sulfate = Reddish/pink​

MgO = Silvery white​

ZnO = White solid​

PbO = Yellow solid​

PbCO3 = White solid​

CaO = White solid​

 

[crisangle]

can you explain me the carbon cycle, dynamic equilibrium , extraction of iron and aluminium

 

[multixamza01]

can you explain me the carbon cycle, dynamic equilibrium , extraction of iron and aluminium

carbon cycle is explained above .
Dynamic equilibrium is the point in a reversible reaction when the rate of forward reaction becomes equal to the rate of backward reaction .

Extraction of Iron and Aluminum is to be done from book . I can't explain it here , too long and i myself have to study

 

[Tharindu]

What is flue gas desulphurIzation????

 

[khanrocks20]

diff bw hydrated and anhydrous copper sulphate?