Chemistry Paper 4-theory- doubts =D

[AlishaK]

I guess it's supposed to be 'CHI3' ...not sure thou.

http://www.chemguide.co.uk/organicprops/carbonyls/iodoform.html

 

[AlishaK]

May b so .... cz NaOH is alkali but still not justified cz its nt mentioned! they gotta mention to draw dat conclusion!!!

http://www.chemguide.co.uk/organicprops/carbonyls/iodoform.html
makes abita sense...bt still :/

 

[Anika Raisa]

http://www.chemguide.co.uk/organicprops/carbonyls/iodoform.html

U knw its better if some things in ms r ignored! Btwn i heard ms r made aftr we give xam! Btwn i agree wid the website!! Until the alkli is mention it is not justified to write Na u c!! BOL 4 xam!

 

[AlishaK]

U knw its better if some things in ms r ignored! Btwn i heard ms r made aftr we give xam! Btwn i agree wid the website!! Until the alkli is mention it is not justified to write Na u c!! BOL 4 xam!

yes! .. lol ... http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_qp_41.pdf
Hey sis just wanna clear one thing 2 e) what happens to the LE and HYD and Soln...cause answer in my notes and ms r diff! for LE thingy.
BOL too!

 

[kiara15]

http://www.docbrown.info/page06/AldehydesKetones.htm informativ

 

[kiara15]

http://www.docbrown.info/page06/AldehydesKetones.htm chck this

 

[marz_katy]

any1 can gv me linnk fr downloading qp and ms of chem p4's old papers...plzzzzzzzzzzzzzzzzzzzz:'(

 

[confused_soul]

Can some body please explain me ph ksp pka ka kc kw stuff
Really need help
Also what about the titration curves we draw for them, i mean do we plot it at the given volume? Or what

 

[xhizors]

for the last one, it's slow cause they both r anions ...that's a right reason too eh?
May Allah bless u mate!! evn if u dnt ask me, I do remember everyone in my prayers... Jazak Allah Khair! btw any tips for app?
Cheerio!

yup yup Exactly, feel prety shy to collide

Tips: study Environmental chemistry, Analytical Chemistry and Design and Material

 

[xhizors]

Can some body please explain me ph ksp pka ka kc kw stuff
Really need help
Also what about the titration curves we draw for them, i mean do we plot it at the given volume? Or what

MashAllah !!
lol
ph=(-log([conc ofH+ or OH-])
ksp= solubility product = [product A][Product B]
For Buffers pH= pka + log([salt]/[acid]) --> its same as finding normal pH but a more simpilified term
pka= -log(Ka)
for ka:
HA <=> H+ + A+
ka= [H+][A+]/[HA]
@ eqilibrium
[H+]=[A+]
so u figure out rest

kc = conc of products/ conc of reagants
kw is a product of ions of water
kw remains same for every solution = 1x10^-14
but for purewater kw = 1x10^-7

i think u are asking about neutralisation curves

if strong acid strong base
graph (awesome)
if weak acid strong base(ooolala)
if strong acid weak base(sneaker)
if weak guys(graph 4 )
see images:
https://docs.google.com/file/d/0Bzq5n8R79M6_UjQ0WUNKT0w2VDg/edit?usp=sharing
https://docs.google.com/file/d/0Bzq5n8R79M6_TmI3ZWJWMUJnZlE/edit?usp=sharing
https://docs.google.com/file/d/0Bzq5n8R79M6_WDFETGxacXctRGM/edit?usp=sharing
https://docs.google.com/file/d/0Bzq5n8R79M6_RThIanpUWVNWaXM/edit?usp=sharing
https://docs.google.com/file/d/0Bzq5n8R79M6_Nzd0Sk1WTk85eE0/edit?usp=sharing

hope this helps buddy!
Please Pray for me

 

[xhizors]

yes! did ma'am vani tell u abt that ms thingy?! jk ;P.. lol ... http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_qp_41.pdf
Hey sis just wanna clear one thing 2 e) what happens to the LE and HYD and Soln...cause answer in my notes and ms r diff! for LE thingy.
BOL too!

It decreases down the group!!
LD(lattice dissociation) decreases down the group (good for solubility)
hyd(hyd) dec down the group(bond length inc) bad for solubility
hydration factors dominates the Lattice dissociation factor hence solubility decreases down the group!!

 

[xhizors]

Sorry to disturb you again but one thing more for the same Q3)e) why is benzene reacting with excess Br(aq) if any catalyst of FeBr2 isnt present ?
knowitall10 if u know plzz help me with this

lol dont say sorry
overload the questions on me i would love that
look due to other functional groups the 2 4 (and 6) position of ring is activated so u don't need any further reagants to Bromonize rings

 

[xhizors]

Jazak Allah khair! is that CI3? but the MS says something else? So it's necessary for a coupling reacn to have alkaline soln?!
Thanks a ton. Stay blessed!

no no bahi its not ChI3 which is attatched
ChI3 is the side product giving yellow ppt
the products are:
NaI3 + h20 + ChI3 + (C6H5Oh)-COONa+
its TriIodo methane test:
u warm the X Compound with NaOh and I2
X compound can only be following
a) Ethanol
b) all secondry alcohols
c) only aldehyde ethanal
d) all methyl ketones
hope this helps!
Pray for me please

 

[xhizors]

we

One more thing. http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_qp_41.pdf
Q3 b) do we have to mention NO+1/2O2 in the middle of the two mountains?

well i was thinking the same but in ms hums are without those products

 

[kiara15]

anyone plz give me chem application notes plzzz??

god help those who help others

 

[AlishaK]

no no bahi its not ChI3 which is attatched
ChI3 is the side product giving yellow ppt
the products are:
NaI3 + h20 + ChI3 + (C6H5Oh)-COONa+
its TriIodo methane test:
u warm the X Compound with NaOh and I2
X compound can only be following
a) Ethanol
b) all secondry alcohols
c) only aldehyde ethanal
d) all methyl ketones
hope this helps!
Pray for me please

everytime it has to b that eqn? what if it's CH3CO instead of C6H5OH, then it'd be CH3COONA? is it?!
Jazak Allah Khair. And no worries, deffo will pray for u! You too remember me in ur prayers.

 

[AlishaK]

anyone plz give me chem application notes plzzz??

god help those who help others

i want it too

 

[AlishaK]

It decreases down the group!!
LD(lattice dissociation) decreases down the group (good for solubility)
hyd(hyd) dec down the group(bond length inc) bad for solubility
hydration factors dominates the Lattice dissociation factor hence solubility decreases down the group!!

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?!

 

[AlishaK]

yup yup Exactly, feel prety shy to collide

Tips: study Environmental chemistry, Analytical Chemistry and Design and Material

study Environmental chemistry, Analytical Chemistry and Design and Material, U mean for the application part?!

 

[xhizors]

everytime it has to b that eqn? what if it's CH3CO instead of C6H5OH, then it'd be CH3COONA? is it?!
Jazak Allah Khair. And no worries, deffo will pray for u! You too remember me in ur prayers.

yup thats the case just u need to balance it!