Category Archives: Organic chemistry

In case of carboxylic acids the OH bond is more polar due to the presence of carbonyl group. The C=O group attracts more electrons towards itself which makes the -OH more polar. Due to higher polarity the magnitude of H-bonding also increase considerably in case of carboxylic acids as compared to alcohols. So the boilingContinue reading “Why the boiling point of carboxylic acids is higher than that of the corresponding alcohols ?”

The reactivity of Aldehydes depend upon two factors . 1 Steric effect :- The reactivity of aldehyde depends upon the fact that the nucleophile will attack on the Carbon atom of the carbonyl group. If it is less crowded the nucleophile can easily approach it and can easily react. So lesser is the hinderance moreContinue reading “Why Formaldehyde is more reactive then other aldehydes? justify .”

in case of aldehydes and ketones there is a carbonyl group present in the molecule as shown below :- The oxygen is more electrongative than the carbon , due this the polarity develops in the C=O bond. The carbon becomes partially positive and the oxygen becomes partially negative . This decreases the electron density onContinue reading “why do aldehydes and ketones undergo nucleophillic addition reaction ?”

It can be done by the following reaction.

The direct hydration of alkene leads to the formation of alcohols. The reaction takes place according to the markovnikov’s rules for addition reaction. For example we can make 2-methyl propan-2-ol (tertiary – butyl alcohol) from 2- methyl propene (Isobutylene) as shown in the above reaction.

The ethylene chlorohydrin can be prepared by the reaction of ethylene with Hypochlorus acid (Hypohalus acid) It is a kind of addition reaction.

It is a type of addition reaction in which the hydroxyl and halogen groups are introduced in alkene molecule . The alkenes react with freshly prepared solution of hypohalus acid. The acid is formed by the reaction of dihalogen with water. The hypohalus acid gives Halohydrin on reacting with alkene.

It is the phenomenon which is seen in case of addition of hydrogen halide in the presence of a peroxide like benzoyl peroxide. The major product in this kind of reaction is the alkane in which the halide is attached to terminal or the less substituted carbon atom as shown below.

This is due to the following reason :- This is in accordance with sytzeff rule that whenever two alkenes are theoretically possible during a dehydrohalogenation reaction , it is always the more highly substituted alkene which predominates . It can also be best understood by the following illustrations showing the stabilizes of primary(1°) , secondaryContinue reading “Why the but-2-ene is major product of beta elimination of 2-Bromobutane ?”

In case of unsymmetrical alkenes the addition of hydrogen halide takes place according to the markovnikov’s rule . During this reaction under markovnikov’s rule the positive part of the attacking reagent joins with the carbon with more number of Hydrogen and the negative part of attacking reagent joins with the more substituted carbon.

We can make haloalkanes from the alkenes by treating them with rhe hydrogen halides HX . Here the double bond is converted into single bond , hydrogen and halogen gets attached to the carbons involved in double bond.

By catalytic hydrogenation we can get the alkanes from the alkenes. The reaction takes place by reacting ethene with hydrogen in the presence of platinum and pladium and Rany nickel (active form of Nickel) Here is the reaction :-

The mechanism involves the following steps :- Step 1 :- In first step the polarity is developed on the bromine molecule , and the partial positive side of the bromine molecule attacks on the carbon atom of the double bond. This leads to the formation of carbocation. Step 2 :- In second step the negativeContinue reading “Mechanism for electrophillic addition reactions of alkenes”

Alkenes give electrophillic addition reactions because of the following reasons:- 1. The pie electrons of the double bond attract electrophiles . 2. The electron density is more on the C-C double bond , so the electrophiles preferably attack on it as compared to the electrophiles which are repelled.

In this reaction the decarboxylation of dicarboxylic acids take place . The potassium salts of dicarboxylic acid give alkene as the COO- group is removed as CO2 , this leads to the formation of double bond between two adjacent carbon atoms.

The complete mechanism takes place in three steps as shown below :- Step 1 :- Step 1 involves the release of Hydronium ion (proton) and then the attack of proton on the lone pair electrons of oxygen. By this way protonated alcohol is formed. Step 2 :- This step is slow and rate determining step.Continue reading “What is the mechanism of acidic dehydration of monohybrid alcohol ?”

By just heating in the presence of methanol we can get the alkene by treating the vicinal dihalides with zinc. Here Is the complete reaction:-

In these kind of reactions the Saytzeff rule is followed. Here is the reaction and its conditions:-