Single Choice

Dehydration of alcohols can be done by using:

AConc. $$H_{2}SO_{4}$$
B$$Al_{2}O_{3}$$
C$$CaO$$
Dboth A and B
Correct Answer

Solution

Dehydration of alcohols can be done by:
a) Using aluminium oxide as catalyst.
This is a simple way of making gaseous alkenes like ethene. If ethanol vapour is passed over heated aluminium oxide powder, the ethanol is essentially cracked to give ethene and water vapour.

b) Using sulphuric acid at a temperature of 170°C.
Concentrated sulphuric acid produces messy results. Not only is it an acid, but it is also a strong oxidising agent. It oxidises some of the alcohol to carbon dioxide and at the same time is reduced itself to sulphur dioxide.

Both of these gases have to be removed from the alkene. It also reacts with the alcohol to produce a mass of carbon. There are other side reactions as well.

Option D is correct.

SIMILAR QUESTIONS

Alcohols, Phenols and Ethers

State how the following conversions can be carried out. Ethyl alcohol to Ethene.

Alcohols, Phenols and Ethers

In the following sequence of reactions, $$CH_3Br\overset{KCN}{\rightarrow}A\overset{H_3O^+}{\rightarrow}B\overset{LiAlH_4}{\rightarrow}C$$ The end product C is:

Alcohols, Phenols and Ethers

Which of the following alcohols will give the most stable carbocation during dehydration?

Alcohols, Phenols and Ethers

Explain mechanism of acid catalyses dehydration of ethyl alcohol?

Alcohols, Phenols and Ethers

The major product of the above reaction is :

Alcohols, Phenols and Ethers

Acid catalysed dehydration of t-butanol is faster than that of n-butanol because:

Alcohols, Phenols and Ethers

Choose the correct answer among the alternatives given: In the following reactions, (i)$$CH_3-\overset{CH_3}{\overset{|}C}H-\underset{OH}{\underset{|}C}H-CH_3\xrightarrow{H^+/heat}\underset{[Major\ product]}A +\underset{[Minor\ product]} B$$ (ii)$$A\xrightarrow[in\,absence\,of \,peroxide]{HBr,dark}\underset{Major\ product}C+\underset{Minor\ product}D$$ The major products $$A$$ and $$C$$ are respectively?

Alcohols, Phenols and Ethers

Name the reagents used in the following reaction: Dehydration of propan-2-ol to propene.

Alcohols, Phenols and Ethers

Which is the best reagent to convert cyclohexanol into cyclohexene?

Alcohols, Phenols and Ethers

In the following dehydration of diol with $$\displaystyle { H }_{ 3 }{ PO }_{ 4 }$$, following product is:

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