organic...............power stuff...

Ans 1... I feel... II > IV > I > III ..btw i have encountered the same question in the SQB Of BT insti...and the options given were

A - I < II < III < IV
B- IV < III < II < I
C- IV < I < II < III
D- III < II < IV < I

since we know that in pyrole the lone pair of N are in conjugation with the ring..so it's gonna be least basic so on that basis answer is D

Ans 2 ...Wen Cl atom leaves..carbocation is formed and the ring attains aromaticity due to which it becomes very^∞ stable....even 10¹⁴ stable than the triphenyl carbocation Ph₃C⁺ ...

Ans3..this one has been discussed here b4..the basic funda of doing this question is to separate the charges and then if the charges are stabalised due to any reason(in this case the reason is aromaticity) then the compound will have dipole momment...
btw the link is :
http://www.targetiit.com/iit-jee-forum/posts/organic-13833.html

Ans 4 ...the topmost COOH grp will be ionised first then the bottom most COOH grp and then the middle one...the reason why i placed the middle one at last is coz the way eure has drawn the diagram there can be a possibility of hydrogen bonding with the fluorine atom...just a guess

1) 2>1>4>3 (agreed wid pritish)

(edited)

4) topmost (-I due to F)=> more acidic
bottommost (+I due to -CH₃)

1. I>IV>II>III

In II (there is -I effect of the N's on each other which will decrease basicity somewhat)

In IV there is a small -I effect of the benzene ring
But still have to verify with actual pKa values

5. A

rest all agreed with what said

I dont have answers for Q2,3,4...so depepedning on u guys to reach a consensus...

btw for Q2....paper asks whether Cl⁺ is formed or Cl^- on ionization

Ans .. obviously Cl^- will be formed on ionisation..so that carbocation is formed and aromaticity is achieved..

@eureka...
which other questions??
i think all questions are answered...u just need to confirm the answers...

Q3...no one has given the ans..

Q4...i dont have answer...so need consensus..

i have given the answer for third question..see post #3
btw I will have more dipole moment..