Organic Test QUestions

Avik...in Q1 -OH is not a bulky enough group that it will force the ortho effect into place. Chelation aur ortho effect alag hain..
which you have so graciously stated in your hidden posts :P

In Q2, X is the correct statement.

Yaar in Q3...Cl ka size zyaada hai toh HCl ka bond length HF se zyaada nahi hona chaiye?

Don't know why ring contraction should even happen in that case...there were some exceptions to Cannizzaro reaction which I remember caused ring contraction. Why would it slip down to 4 member when 5 member is more stable?

1) But,,, i was taught,,,tht due 2 ortho eff.in Benzoic Acid....if any group is attached at Ortho (any group), its acidity wud increase.
& Pritish, Then toh agar Cl/Br/CN bhi hoga toh bhi koi effect nahi hona chahiye....??

2) Meri hidden reasoning toh padho..

3) I think same.

Haan Avik those are not bulky groups. Ortho effect is not applicable for them....I read this on yahoo answers..the guy who answered was finishing his PhD in chemistry.
http://answers.yahoo.com/question/index?qid=20071012080118AABWL03
Zaahir si baat hai ki the group has to be bulky. It forces carboxyl group out of the plane.

Avik mere pyaare, dulaare, pinku, chintu, etcetc bhai....do NOT compare S_NAr to EAS. Never. Comparing those two on the same basis is nothing but a crime which makes you liable to the CID.
What prevents SN in aryl substrates? Their delocalised electron density. What reduces this density? Deactivating groups. Will substitution become easier? YES.
All S_NAr needs is a leaving group and something which reduces its electron density, making approach of nucleophile easier. Capiche?
And you were asking on chat about terminal alkynes giving Tollen's test. Actually baat yeh hai ki terminal alkyne mein removable hydrogen hota hai. This is replaced by metal atom in acid base type reaction. It gives a ppt of metal acetylide.
For eg, ethyne reacts with tollen's reagent to give AgC(triple)CAg, which has a yellow colour(not sure about the colour).

Fr 2) :O U picked it right....I was Thinking of EAS all this while.

Thnx...(Lekin itna bada essay likhne ki zaroorat nahi thi :P)

(btw whts "Capiche"..?)
& "Paste" ka woh matlab nahi tha :)

lola...phir toh OH ka asar pad raha hai...lekin halogens mein asar nahi pad raha tha!
I didn't paste. I wrote it.
Capiche means understand in italian :P

Chloro Derivatives of Benzoic ACid mein bhi asar pad rahaa hai.

See the pKa Values-
o-Cl-BenzoicAcid (2.92), meta-derivative (3.8), para derivative (3.98)

Hmm..achcha that comparison was between fluoro and chloro benzoic acids.