ANY DOUBTS HERE!!!

[nid404]

Q19) A chiral center has 4 different groups attached to the carbon
I'll circle the carbons which have a chiral center...check the attachment

[sweetie]

but the carbon atom attached 2 da OH group has only 3 groups attached to it.. where is da 4th one?

[nid404]

A chiral centre is a carbon centre with four different groups(they could be any group...not necessarily carbon groups.....the fourth bond is with a hydrogen...)

[sweetie]

Thank You
got it

[nid404]

gr8 

[nid404]

20) 2 abt each double bond makes 6
further if u consider the whole chain, ull find 2 more...
actually it'll take tooooooo much time to draw the whole thing out....but if u really want it, i shall do it tom and scan it

28)2,4 DNP reacts with carbonyl compound with C=O group

1 already present...
2 formed at the other 2 double bonds

[sweetie]

if a carboxylic acid was formed, will da c=o group in da acid react with 2,4 DNPH ??

thanx so much , i really appreciate ur help

cud u also help me in Q4 , 29 of da same year???

[nid404]

no it doesn't react with carbonyl groups in acids,esters and amides

[nid404]

k
Q4) D

first thing when u c these graphs..look for the obvious
you know 18 protons/eletcrons....electronic configuration 2.8.8 so 0 unpaired electrons....it will be either B or D
Now look at the other proton numbers....you knw electrons are filled singly until there is no more space to....
So upto proton no 15, it is filled singly, no of unpaired electrons increase. Then, they start pairing up, after proton no 15, reducing the no of unpaired electrons.
eg. take 15 electrons
1s²2s²2p⁶3s² 3p³
the 3 electrons in the p subshell are in the 3 different orbitals and so 15 has the max no of unpaired electrons...3

[nid404]

Q29) D

check where the OH groups r
in A, B n C if dehydration happens, double bonds will form as shown in the compound but in D, one OH group is in the centre, which will not give a double bond like desired in the two ends.

I hope ur getting me

[sweetie]

ya got it
Thank You

[sweetie]

Which of the following would behave most like an ideal gas at room temperature?

A carbon dioxide

B helium

C hydrogen

D nitrogen

da answer for this is helium, but why cant it be hydrogen?

[nid404]

Hydrogen is reactive..

It will have intermolecular force...they exist as diatomic molecules which is not close to being an ideal gas at all

[ruby92]

o/n 2004 paper 2
Q 28
39(why is 2 wrong?)
35(why not 3)
34(why is 3 right, wont half filled orbitals have high IE values?)
33(why not 2 and 3)

m/j 2004 paper 1
28) D agn
monosubstituted alkene, one R group is attached to the carbon-carbon double bond. Not oxidized by mild oxidising agents

i dont understand this
 

[Sue T]

i have some more chem questions :
w 02
3) Use of the Data Booklet is relevant to this question.
In the gas phase, aluminium and a transition element require the same amount of energy to form
one mole of an ion with a 2+ charge.
What is the transition element?
A Co
B Cr
C Cu
D Ni

the other 2 are attached -i couldnt copy paste

mj06
2 A sample of chlorine containing isotopes of mass numbers 35 and 37 was analysed in a
mass-spectrometer.
How many peaks corresponding to Cl₂⁺ were recorded?
A 2
B 3
C 4
D 5