what is A and B?????
Answers
Explanation:
While naming any functional group, it's a convention that the longest carbon chain includes the functional group. As ether is a functional group, most of us may consider it a part of the longest carbon chain.
Well it's quite the opposite in case of Ethers. Here are the rules for naming an ether:
The alkoxy groups with shorter carbon chain is a substituent
The longer carbon chain is the parent chain
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2
Phenols do not show any visible reaction with carboxylic acids because both are acidic in nature.
If that was the case, then alcohols and carboxylic acids wouldn't have reacted with each other and the world would've been deprived of esters!
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So, the reason is not correct. We need to investigate what may be the reason. For that, let us look at the mechanism of the esterification reaction:
Step 1 : It involves the formation of carbocation
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Step 2: Involves the attack of electron rich oxygen of alcohol on the carbocation.
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Step 2, where the alcohol group attacks the electrophilic carbon atom of the carboxylic acid is the rate determining step in an esterification reaction.
This step is, however not possible with phenol, because the lone pair of electrons on oxygen is not available readily for donation due to resonance.
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As a result, step 2 becomes very slow with phenol, making it difficult to form an ester.
Conclusion: Phenol doesn't react with carboxylic acids, not because it is acidic, but because electrons are not available on the phenolic oxygen for attack on the carbocation.
3
Alcohols only exhibit acidic behaviour.
Well you're in for a surprise if you think that alcohols are only acidic in nature.
Alcohols are both acidic and basic in nature. Hence, are amphoteric.
We know alcohols are weak Arrhenius acids - they can donate a proton in an aqueous solution to form an alkoxide ion. Alkoxide ion is a strong conjugate base which shows that alcohols are weak acid.
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But that's not all. Alcohols can show basic behaviour as well. That is, they are amphoteric in nature. Alcohols act as strong Lewis bases in presence of strong acids like HX. They tend to donate electrons under these conditions.
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