Chemistry: Post your doubts here!

[applepie1996]

Really?!? I've never heard the phrase before???

good to know
then i must tell you that ....You mam are one of the luckiest people alive to have not heard this torturing phrase before

 

[daredevil]

nope i saw it yesterday when we were at the maths forum it says female right there above lahore i can read lol

hahah yeah well stil some just don't pay attention to it thats the funny part .... and let's stop discussing my controversies here or the xpf police might arrest us

 

[MaxStudentALevel]

Ye.. i hadnt either until my teacher burst the bubble

Woah. Where does it apply??

 

[Jiyad Ahsan]

By the way, one of the papers asked us to mention the range of the thermometer and the mark scheme was something like "depends on the candidate's expts". so do u have any idea what the range might be? and what must the graduations be between each value on the thermometer. Some said it's 0.5'C and some say it's 0.1-0.2'C....

it depends on what you're measuring.. you know.. if you're boiling something it doesnt matter much but if its like you're measuring specific heat capacity or something.. take accuracy at 0.5 degrees, then write in the additional details that a more accurate thermometer (0.1 degrees) would be more accurate bla bla

and keep the range something umm sensible like if you're working with water 0 - 100 would be fine..

 

[MaxStudentALevel]

By the way, one of the papers asked us to mention the range of the thermometer and the mark scheme was something like "depends on the candidate's expts". so do u have any idea what the range might be? and what must the graduations be between each value on the thermometer. Some said it's 0.5'C and some say it's 0.1-0.2'C....

Depends on your experiment! If you're estimating Or using like 0-100 or 0-500 degree changes it depends on that!

 

[knowitall10]

Aoa wr wb

Can someone please draw a diagram for qn 1 of this paper ?

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_52.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_ms_52.pdf

Thanx a lot


PS: I'd really appreciate if someone can upload solved paper 5s for chemistry qn 1 of different years, thanx

wa alykumussalam... i did it, but its so damn messy!!
I'll do a neater version and i'll upload it soon inshAllah

 

[MaxStudentALevel]

Excellent excellent excellent MashAllah. This is exactly what i was looking for here! Thanks a lot! That was the best response ever!!!!!!
Jazak Allahu Khair!

That was actually from a different thread specially for P5. Written by someone else

 

[knowitall10]

it depends on what you're measuring.. you know.. if you're boiling something it doesnt matter much but if its like you're measuring specific heat capacity or something.. take accuracy at 0.5 degrees, then write in the additional details that a more accurate thermometer (0.1 degrees) would be more accurate bla bla

Oh alright, thanks

 

[MaxStudentALevel]

inorganic chapters (periods and groups) are pain in da A$$ chapters!!!

IKNOWRIGHT

 

[knowitall10]

That was actually from a different thread specially for P5. Written by someone else

Haha.. i don't really like to look through stuff, someone i know said that most of your questions are answered on this thread so i just shot a quick glance on the others and mainly concentrate and replying and recieving replies on this thread

 

[MaxStudentALevel]

good to know
then i must tell you that ....You mam are one of the luckiest people alive to have not heard this torturing phrase before

Ahahahahaaaa lol! I wouldve been lucky if I had never heard the word "Chemistry" Madame. I think a little more toruture will have no real effect xD

 

[Soldier313]

wa alykumussalam... i did it, but its so damn messy!!
I'll do a neater version and i'll upload it soon inshAllah

I don't mind the messy one as long as it's legible
just need something concrete to understand

 

[MaxStudentALevel]

Haha.. i don't really like to look through stuff, someone i know said that most of your questions are answered on this thread so i just shot a quick glance on the others and mainly concentrate and replying and recieving replies on this thread

Lol oh alright! Btw you live in Saudi? That's amazing, it's a dream of mine to live there!

 

[Jinkglex]

I dont really remember who said it but if it wasnt answered a brief summary of the inorganic chapters is:

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]

Does this help?

 

[A star]

I dont really remember who said it but if it wasnt answered a brief summary of the inorganic chapters is:

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]

Does this help?

awesome man

 

[A star]

https://skydrive.live.com/view.aspx?resid=AD7CCA97726D5367!609&app=Word&authkey=!AOrbkXaV2yJ3QJkfor organic

 

[MaxStudentALevel]

I dont really remember who said it but if it wasnt answered a brief summary of the inorganic chapters is:

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 t
he H2S04 into S03 then S then H2S]

Does this help?

Yes! That's really efficient!

 

[MaxStudentALevel]

https://skydrive.live.com/view.aspx?resid=AD7CCA97726D5367!609&app=Word&authkey=!AOrbkXaV2yJ3QJkfor organic

OHMYGOSH YOUR ICON THINGY IS OERFECT XD

 

[Jinkglex]

anytime! please do feel free to ask me for any other summaries, it helps my revision also, and feel free to contribute

 

[A star]

anytime! please do feel free to ask me for any other summaries, it helps my revision also, and feel free to contribute

krne hae to sara kr do book kkholna nahe pare gi