Chemistry Paper 4-theory- doubts =D

[xhizors]

if hydration dominates then it'd soluble?! and i was talking abt the lattice energy? it increases down the grp as the ionic character increases cause the polarising ability decreases! I never learnt what u just stated...Or maybe i can't comprehend it? I'm sorry. Elaborate if u can?!

If u are asking about G2 Solubility trend:
it decreases down the group
due to two factors:
a)solubility inc as hydration inc as hydration gives out energy good for breaking lattic
down the group hydration decreases as G2 elements form weak water bonds! means less energy available now for lattice to break
b) Lattice Dissociation energy decreases down the group less energy required to break the lattice
but even though hydration energy decreases so much that it cant be able break the lattices
so over all it decreases down the group
i dont know whether it answered your question or not?

 

[AlishaK]

If u are asking about G2 Solubility trend:
it decreases down the group
due to two factors:
a)solubility inc as hydration inc as hydration gives out energy good for breaking lattic
down the group hydration decreases as G2 elements form weak water bonds! means less energy available now for lattice to break
b) Lattice Dissociation energy decreases down the group less energy required to break the lattice
but even though hydration energy decreases so much that it cant be able break the lattices
so over all it decreases down the group
i dont know whether it answered your question or not?

yea got it!!
Thanks.

 

[xhizors]

so when they only for the organic product, it has to be RCOONA? 0.0
Sorry im bugging u so much! Is there any advice u cd give me for app. It doesnt get in my head! :/

no i mentioned the compoundss which it can be use for
also for app just go through the text book
or post it here specific issue/concept and i'll try to help!!

 

[AlishaK]

no i mentioned the compoundss which it can be use for
also for app just go through the text book
or post it here specific issue/concept and i'll try to help!!

okay, if u have time then a bit of explanation of NMR, analysing that graph thing with narrow mountains (not eaxctly). And yea Main points for the chromatography methods, PC, TLC, GLC, HPLC...
Thanku! and i was talking abt this question in O/N 2012 Q5 b) third one. don't mind taking a look? they r asking for the organic product formed with that iodoform test.

 

[AlishaK]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s12_qp_41.pdf
Q2 i) just wanna confirm.
xhizors
Jazak Allah khair!

 

[AlishaK]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s12_qp_41.pdf
Q2 iv. xhizors
knowitall10

 

[knowitall10]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_41.pdf
Q2 iv. xhizors
knowitall10

[Fe(H2O)6-n(NO2)n]^2+ (n=1 to 6)

 

[AlishaK]

[Fe(H2O)6-n(NO2)n]^2+ (n=1 to 6)

How do we get that? o.o And Q2 b (iv). Q2 c (ii)

 

[AlishaK]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s12_qp_41.pdf
Q3 b i) why isnt it electrophilic addition, how is it redox or redn?! :s

 

[kiara15]

get specific what u want specifically
maybe i can help !

ameen, i need notes of electrophrsis, design and material? plzzz can u?

 

[kiara15]

i want it too

ohh

 

[knowitall10]

How do we get that? o.o And Q2 b (iv). Q2 c (ii)

Honestly speaking....i did that question aaaaaaages ago..so even my memory can be like that of an old woman..i dont remember :/
Q2 b(iv) either step 2 cz it involves H2 and O is formed from NO
or step 3 since it involves H2 and N2O formed from NO...
C (iii) i think u add all of them..i dunno what the heck made me erase it :/...but i can see the outlines...i've ...added them...yep Add all the three...what does the mark scheme say?

 

[knowitall10]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_41.pdf
Q3 b i) why isnt it electrophilic addition, how is it redox or redn?! :s

cuz there's a reversible sign.....and cz electrophilic addition is in alkenes

 

[AlishaK]

Honestly speaking....i did that question aaaaaaages ago..so even my memory can be like that of an old woman..i dont remember :/
Q2 b(iv) either step 2 cz it involves H2 and O is formed from NO
or step 3 since it involves H2 and N2O formed from NO...
C (iii) i think u add all of them..i dunno what the heck made me erase it :/...but i can see the outlines...i've ...added them...yep Add all the three...what does the mark scheme say?

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s12_ms_41.pdf

 

[AlishaK]

cuz there's a reversible sign.....and cz electrophilic addition is in alkenes

okay how exactly is it redox or redn whatever? Please please please...! :/

 

[knowitall10]

okay how exactly is it redox or redn whatever? Please please please...! :/

type of reaction --Electrophilic addition is a mechanism plus it's reduction cz of the gain of H atoms...see that diagram? Look, both the O's have a hydrogen atom now...

 

[knowitall10]

ameen, i need notes of electrophrsis, design and material? plzzz can u?

chemguide.co.uk
follow this link..it's very good. Go to CIE syll. support

 

[AlishaK]

type of reaction --Electrophilic addition is a mechanism plus it's reduction cz of the gain of H atoms...see that diagram? Look, both the O's have a hydrogen atom now...

i thought so just wasnt confident...thanks a ton, Also, Q3 a, where the aryl ring is joined to that pentagon: don't we count C1-C2 as in C1 from the aryl and C2 from the penta thingy. they just counted one C atom there.:/ In some other sheet i once did this wasnt the case

 

[AlishaK]

[Fe(H2O)6-n(NO2)n]^2+ (n=1 to 6)
explain?! xhizors
Q3 (D) why is that ketone getting reduced to -OH using Ni? !
I never learnt that Ni cn b used for ketones redn?!
Do u know? knowitall10

 

[AlishaK]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_41.pdf
3 d Why Br on the benzene ring is in position written in the ms? can't put 'em (non-adjacent thou) anywhere? like 1st nd 5th position?
PhyZac
xhizors