some organic dbts

bhaskar see #7. the answer is (C)

ohh im sry dimensions is correct... for Q3. 1>3>2>4

the ans for the 3rd 1 acc.to me should be 3>1>2>4 bcoz more less the delocalisation moer basic is the compound & also more the no.. of lone pairs of elec.. more basic it is....
wats ur ans??? mr.asish

@manish sir: the pKa values of methanol = 15.5 and pKa of water = 15.74 i found on Wikipedia and obviously phenol is more acidic than methanol .. so it should be (c)

pKa value of water can be easily calculated to be 15.74
as Ka of water = [H+][OH-]/[H₂O]
= (1*10^-14)/(55.55)
So, pKa of water = 14 + log(1000/18) = 17 - log(18) = 15.74

pKa of methanol = 15.5 from wiki
http://en.wikipedia.org/wiki/Methanol

ya that must be p>o>m mite be a typo ...
@dimensions, john and bhaskar: out of all aliphatic alcohols, only methanol is stronger than water (acidic) all other aliphatic alcohols are weaker check post #7

1>3>4>2 (not sure bout 2)

a)

for 2nd one

m-<-o<-p

For Q1. see this:
http://www.goiit.com/posts/list/organic-chemistry-my-question-is-why-ch3oh-is-more-acidic-than-41366.htm
and
http://wiki.answers.com/Q/Why_is_methanol_more_acidic_than_water

quoting wiki answers:
Methanol is only slightly more acidic than water. The measure of the strength of an acid is its pKa value.

The pKa of water is 15.7 and for methanol it is 15.5.

The difference is primarily due to the stability of deprotonated negatively charge ion, or anion. When you deprotonate water you are left with the hydroxide ion, or OH-. When you deprotonate methanol (CH3OH), you are left with CH3O-. The larger the anion, the more the negative charge can be spread out (reducing the charge density) and this stabilizes negatively charge species.

Because CH3O- can better stabilize the negative charge than OH-, the resulting anion is more stable. However, they have nearly identical acidities!

Q2. acidity order among nitrophenols is in the order?

h2o ka acidic nature kam hai phenol se ??

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