Chemistry P4| A2 only

[smzimran]

please post a link if anyone has the O/N 2011 ER ?

http://www.clickpapers.net/alevelpastpapers/chemistry/9701_w11_er.pdf

 

[zenyatales]

http://www.clickpapers.net/alevelpastpapers/chemistry/9701_w11_er.pdf

( : thanks!

 

[Amy farvin]

http://www.xtremepapers.com/papers/... AS Level/Chemistry (9701)/9701_s10_qp_42.pdf
plz explain me thi question 6(d)

 

[princesskt]

Carbon does not have enough orbital space to accomodate electrons of dative bond by chlorine!
It has no d orbital space!

can u plz draw the structure............

 

[saudha]

how do u get a ketone and a carbon dioxide in addition to 2 methyl propane...with hot concentrated KMNO4

 

[Amy farvin]

how do u get a ketone and a carbon dioxide in addition to 2 methyl propane...with hot concentrated KMNO4

i too dont get it,to explain u.. if anyone knowz plz help us...

 

[saudha]

http://www.chemguide.co.uk/organicprops/alkenes/kmno4.html

pls some one tell me at the end of this page there is a question in this summary ....... related to this:

how do u get a ketone and a carbon dioxide in addition to 2 methyl propane...with hot concentrated KMNO4

i too dont get it,to explain u.. if anyone knowz plz help us...

 

[girlscampisra]

how do u get a ketone and a carbon dioxide in addition to 2 methyl propane...with hot concentrated KMNO4

i too dont get it,to explain u.. if anyone knowz plz help us...

when double bond breaks , the primary carbon forms co2 , secondary forms carboxylic acid while tertiary forms ketone.. as u can see double bond is between primary n tertiary carbon the products will be co2 n ketone!

 

[girlscampisra]

and its 2 methyl propENE not proPANE!

 

[saudha]

when double bond breaks , the primary carbon forms co2 , secondary forms carboxylic acid while tertiary forms ketone.. as u can see double bond is between primary n tertiary carbon the products will be co2 n ketone!

wht do u mean by primary tertiary and secondary carbon?

 

[girlscampisra]

wht do u mean by primary tertiary and secondary carbon?

primary carbon which is attached to one carbon only.. secondary which is attached to 2 carbons n tertiary which is attached to 3 carbons..

in 3 methyl propene the methyl carbon is primary as its attached to 1 carbon only so forms co2 while 2nd carbon of propene is a tertiary carbon so forms ketone!

 

[hassam]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s10_qp_42.pdf
plz explain me thi question 6(d)

Candidates should be aware that all
β-sheets contain (roughly) the same density of hydrogen bonds – between the C=O and N-H
groups in the peptide bonds of adjacent chains. The side chains poke up and down from the plane
of the sheet. It is the interactions of these side chains between the sheets that is important for
flexibility: if these interactions are weak van der Waals (as in silk, with glycine and alanine
residues), then the sheets are flexible, If, however, the interactions are covalent S-S bridges, then
the sheets cannot slide over each other so easily, and so are more rigid.

 

[hassam]

Why HFCs breakdown quickly in lower atmosphere even though C-H bond is stronger than C-Cl bond?

 

[histephenson007]

and its 2 methyl propENE not proPANE!

Man, I was gonna answer this question long time ago, but saw propane and thought that this was something new. but...phew nothing new

 

[histephenson007]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s10_qp_42.pdf

This paper is kinda tough. Does anyone know the GT for this?

Meanwhile, my questions from dis papers :

2.b) Can someone explain the calculations. Again, I've said this before, WHY is lattice enthalpy positive?!
3.d)i) dafuq?? we should find out the answers by trial and error method or what/??? also include ii) plz
5.d)ii) I don't get why we need to add NaOH at the end?!

Please help me, you're sure to get a like even for trying, I'm a likaholic

 

[Zishi]

Why HFCs breakdown quickly in lower atmosphere even though C-H bond is stronger than C-Cl bond?

Can you provide the stem of the question?

 

[girlscampisra]

Man, I was gonna answer this question long time ago, but saw propane and thought that this was something new. but...phew nothing new

haha i got confused in the first place too!

 

[hassam]

Can you provide the stem of the question?

well....it was written in the book.....so this cnfusion came into my mind

 

[hassam]

c

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s10_qp_42.pdf

This paper is kinda tough. Does anyone know the GT for this?

Meanwhile, my questions from dis papers :

2.b) Can someone explain the calculations. Again, I've said this before, WHY is lattice enthalpy positive?!
3.d)i) dafuq?? we should find out the answers by trial and error method or what/??? also include ii) plz
5.d)ii) I don't get why we need to add NaOH at the end?!

Please help me, you're sure to get a like even for trying, I'm a likaholic

5d ii.....with HCl the basic phenylamine will immediately react to for C6H5NH3+Cl-...bt we wanted just plain old phenyl amine....dats why we add NaOH

 

[girlscampisra]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s10_qp_42.pdf

This paper is kinda tough. Does anyone know the GT for this?

Meanwhile, my questions from dis papers :

2.b) Can someone explain the calculations. Again, I've said this before, WHY is lattice enthalpy positive?!
3.d)i) dafuq?? we should find out the answers by trial and error method or what/??? also include ii) plz
5.d)ii) I don't get why we need to add NaOH at the end?!

Please help me, you're sure to get a like even for trying, I'm a likaholic

gt for this was 54! no wonder why! n yeah question 3 d is just trial n error type question!