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New answer posted
a year agoContributor-Level 10
11.39
The preparation of ether by acid dehydration of primary alcohol involves the nucleophilic addition of alcohol molecule to the protonated alcohol molecule as shown below: -
However, under these conditions secondary and tertiary alcohols forms alkenes rather than ethers. The reason for this being that due to stearic hindrance, nucleophilic attack by the alcohol molecule on the protonated alcohol molecule does not take place. Instead protonated 20 and 30 alcohols lose a molecule of water to form stable carbocations. The stable carbocations so formed prefers to lose a proton to form alkenes instead of forming ethers by undergoing
New answer posted
a year agoContributor-Level 10
11.38
According to the question we have to perform the following conversion: -
The above conversion can be done easily by dehydrating 1- propanol with conc.H2SO4 at 413 K.
The mechanism of the above reaction is as follows : -
The mechanism is given below: -
In the first step, the alcohol gets protonated by the acid present to give a protonated alcohol.
In the second step, the nucleophilic attack of another alcohol molecule on the protonated alcohol gives us 1-propoxypropane as the desired product.
New answer posted
a year agoContributor-Level 10
11.37
Williamson synthesis is basically a SN2 reaction of a primary alkyl halide with an alkoxide ion. The basic mechanism for this reaction is
Now consider this reaction,
This reaction proceeds as conventional Williamson synthesis. But if secondary or tertiary alkyl halides are taken in place of primary alkyl halides, then elimination would compete over substitution reaction, which will result in the formation of alkenes. The reason is alkoxides are better nucleophiles as well as strong bases. Therefore, they react with alkyl halides resulting in an elimination reaction.
New answer posted
a year agoContributor-Level 10
11.36
During the reaction, an alkoxide ion is formed which is then added to an alkyl halide to form the ether via SN2 mechanism.
In the primary step, the nucleophile is formed (O- ) which will the approach to the alkyl halide and after the transition stage, the substitution takes place.
During the reaction, an alkoxide ion is formed which is then added to an alkyl halide to form the ether via SN2 mechanism.
During the reaction, an alkoxide ion is formed which is then added to an alkyl halide to form the ether via SN2 mechanism.
During the reaction, an alkoxide ion is formed which is then added to an alkyl halide to form the ether via
New answer posted
a year agoContributor-Level 10
11.35
1-Ethoxy-2-methylpropane
2-Chloro-1-methoxyethane
4-Nitroanisole
1-Methoxypropane
1-Ethoxy-4,4-dimethylcyclohexane
Ethoxy benzene.
New answer posted
a year agoContributor-Level 10
The resonance structures have
(i) The same positions of nuclei, and
(ii) The same number ofunpaired electrons.
New answer posted
a year agoContributor-Level 10
The resonance effect is defined as 'the polarity produced in the molecule by the interaction of two π -bonds or between a π -bond and lone pair of electrons present on an adjacent atom'. The effect is transmitted through the chain. There are two types of resonance or mesomeric effect designated as +R and-R effect.
The atoms or substituent groups, whichrepresent +R or –R electron displacementeffects are as follows:
+R effect: – halogen, –OH, –OR, –OCOR, –NH2, –NHR, –NR2, –NHCOR,
– R effect: – COOH, –CHO, >C=O, – CN, –NO2
New answer posted
a year agoContributor-Level 10
The presence of alternate single and double bonds in an open chain or cyclic system is termed as a conjugated system. These systems often show abnormal behaviour. The examples are 1, 3- butadiene, aniline and nitrobenzene etc. In such systems, the π -electrons are delocalised and the system develops polarity.
New answer posted
a year agoContributor-Level 10
Hyperconjugation is a general stabilising interaction. It involves delocalisation of σ electrons of C—H bond of an alkyl group directly attached to an atom of unsaturated system or to an atom with an unshared p orbital. The σ electrons of C—H bond of the alkyl group enter into partial conjugation with the attached unsaturated system or with the unshared p orbital. Greater the hyperconjugation, greater will be the stability of alkenes.
No, hyperconjugation is not a temporary effect. It is a permanent effect.
New answer posted
a year agoContributor-Level 10
Steam distillation is applied to separate substances which are steam volatile and are immiscible with water. In steam distillation, steam from a steam generator is passed through a heated flask containing the liquid to be distilled. The mixture of steam and the volatile organic compound is condensed and collected. The compound is later separated from water using a separating funnel. In steam distillation, the liquid boils when the sum of vapour pressures due to the organic liquid (p1) and that due to water (p2) becomes equal to the atmospheric pressure (p), i.e. p =p1+ p2. Since p1 is lower than p, the organic liquid vaporises at
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