Chem AS p21/22/23

[confused_soul]

Hiii every one
I dont see much of discussion going about p2 chem
Wer are u guys?

Lets discuss and share short notes

 

[mrnt3250]

Organic Reactions, Revised Version

 

[confused_soul]

Does nt any body has notes compiled they wer posted here last year of past papers cant seem to find them
Hows ur prep ? Thanks for posting this

 

[mrnt3250]

Does nt any body has notes compiled they wer posted here last year of past papers cant seem to find them
Hows ur prep ? Thanks for posting this

You mean revision notes?
Well I've just finished revision, I need to start doing past papers today.
(I actually finished may-june 2002-2012 some time before, but I forgot it)

 

[confused_soul]

Yes revision notes
Well same here
And i am so stressed if i ll be able to go through past papers cuz i did them long ago

 

[mrnt3250]

Yes revision notes
Well same here
And i am so stressed if i ll be able to go through past papers cuz i did them long ago

Man just don't care, revision notes are more important.
Well, my teacher gave me this nice website.
http://www.knockhardy.org.uk/ppoints.htm
Good for quick revisions.

 

[Shai_n]

i wish i had started solving past questions a long time ago

 

[confused_soul]

me tooo i am so doomed !!!!!!!!!!

 

[confused_soul]

Man just don't care, revision notes are more important.
Well, my teacher gave me this nice website.
http://www.knockhardy.org.uk/ppoints.htm
Good for quick revisions.

thanks mate !

 

[Shai_n]

the painful part is that i have to write igcse chemistry p1 and p6 and AS Chem 2 tomorrow!!

 

[confused_soul]

may God's grace be with you !!!

 

[biba]

may the odds be ever in our favour!
good luck guys!

 

[Resha rimaz]

why is there not much dicussion abt chem p22 in xtreme?????????????????????????
Nyway best of luck 2 all...................Pls include me ur precious duas

 

[Toomuch1995]

I think so everyone is busy studying :/

 

[confused_soul]

Where is every body :S
Good luck to all mates
May Allah ji's grace be on us <3
Jazak Allah

 

[DYHAM finals]

mrnt3250 Hey do you have notes for all the AS chapters in chemistry like the organic chemistry If you have pleaseee post coz I am dying...

 

[howtobeaA*student]

Seriously I really want to get A* but how any extra notes anyone?
mrnt3250 that was amazing

 

[PANDA-]

mrnt3250
I don't think F2 can undergo free radical substitution. F-F bond has a very high bond energy to be broken by UV.

 

[Jinkglex]

Some summaries i posted in the post doubt here thread of chemistry, you guys might want to give those a look:

All period 3 elements react with Oxygen [except argon, ofcourse]

They form oxides and burn with varying flame colors [White for MG/AL, blue for sulphur, yellow for phosphorous etc] The oxide formula depends on their valency and some exist as different oxides [e.g SO2, SO3].

They form chlorides [except Chlorine, ofcourse, and argon] as well, but these usually have a constant formulae.

They will ALWAYS BE POSITIVE OXIDATION NUMBER as they react with elements MORE ELECTRONEGATIVE THEN THEMSELF.

For example Na gives Na+ usually, makes Na2O
Mg gives Mg2+, gives MgO

Nitrogen and Sulphur:

N2 is highly unreactive due to N-N triple bond
N reads with O to give NO in car exhausts due to high heat, further oxidised to NO2 by air, mixes with H20 in rain to give acid rain
S reacts with O to give SO2 in car engines, SO2 can be oxidised by NO2 to give SO3, or mix with H20 to give acid rain
Haber process consists of N2 and H2 mixed under conditions:
450C
200 ATM pressure
Iron catalyst

Exothermic process, Ammonia made and tapped out, later used for fertilizers

Sulphuric acid made by Contact process

Reactions include:

S+O2 -> S02
S02+O2-> S03 THIS IS REVERSABLE REACTION AND ALSO USES VANADIUM {V} OXIDE CATALYST
SO3+H20-> H2S04 [THIS REQUIRES US TO USE 98% SOLUTION OF H2S04 AND H20 TO AVOID MIST FORMING OF H2S04]

CONDITIONS INCLUDE:
450C
1-2 ATM
VANADIUM [V] OXIDE CATALYST.
H2s04 also used in cleaning, fertilizers etc.
S02 and S03 used to preserve food as they inhibit growth of bacteria. Work best at acidic mediums.

ORGANIC:

free radicals made using UV light
NAOH [AQ] forms OH nucleophile [NAOH aq can also do HYDROLYSIS]
NAOH [ethanol] does elimination reaction
AL203 does cracking and elimination/dehydration
ALCL3+CL2 generates Chlorine ELECTROPHILE.
PCL5/SOCL2 generate Chlorine NUECLEOPHILE.
Above can be used for any Halides btw.
Br[AQ] does electrophilic ADDITION
Electrophilic substitution is not part of AS syllabus
NACN+HCL generates HCN for nucleophilic ADDITION
KCN [Ethanol] generates CN NUECLEOPHILE
Conc H2S04 does ESTERFICATION, DEHYDRATION, AND HYDROLYSIS

group 2 forms 2+ ions, their formulae always ends in [X] s2 [2 electrons in S-subshell]
Their nitrates and carbonates get harder to decompose going down the group, as the polarising power of the cations decreases DUE TO their increasing size but constance of their charges [Always remains +2]
The sulphates solubility gets lower down the group, the Hydroxides solubility increases down the group
They get generally more reactive down the group due to easier loss of electrons

Group VII are halogens, usually exist in -1 ionic state
Reactivity and oxidising ability decreases down the group [F is best, As is worst]
Can displace someone BELOW their group from an aqeous solution of its salt or compound.
Can undergo disproportionation reactions in which their oxidation states are liable to be different after the same reaction.
Can be recognized by their reactions with AGNO3 in NITRIC ACID. Their ppt gets thicker and creamier going down the group [White for CL, Yellow for Iodine] and also decreases its solubility in AQEOUS NH3 [Cl dissolves in dilute, Br in concentrated, Iodine in neither]
Can be oxidised by H2S04 with increasing ease down the group -> HCl, Hbr->Br2, HI->I2->[can reduce the H2S04 into S03 then S then H2S]

Cheers and ask questions if you like, and do remember me in your prayers

 

[Machikne]

the painful part is that i have to write igcse chemistry p1 and p6 and AS Chem 2 tomorrow!!

write? you mean "sit" for an exam right??