Methods of Preparation of Alkenes

IMPORTANT

Methods of Preparation of Alkenes: Overview

This Topic covers sub-topics such as Preparation of Alkenes, Preparation of Alkenes by Dehydration of Alcohols, Preparation of Alkenes by Dehydrohalogenation of Alkyl Halides and, Preparation of Alkenes by Kolbe Electrolysis Reaction

Important Questions on Methods of Preparation of Alkenes

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Which of the following compound is formed on acid dehydration of ethanol?

EASY
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2-hexyne gives trans-2-hexene on treatment with –

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Hydrogenation of the adjoining compound in the presence of poisoned palladium catalyst gives –

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The reagent(s) for the following conversion,

   

is/are

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Cyclohexene is best prepared from cyclohexanol by which of the following?

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Among the following compounds which can be dehydrated very easily is

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Identify the set of reagents/ reaction conditions ('X' and 'Y') in the following set of transformations.


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The compound that undergoes dehydration most readily is

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From which one of the following both ethylene and acetylene could be prepared in a single step reaction?

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Which of the following reagent can be used to synthesize the products?

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Which of the following methods cannot be considered suitable for preparing ether?

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Which of the following reagents is used in converting in trans-form GI
   

 

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0.396 gm of a bromoderivative of a hydrocarbon (A) when vapourised occupied 67.2 ml at NTP. On reaction with aqueous NaOH (A) gives (B). (B) when passed over alumina at 250oC gives a neutral compound (C), while at 350oC it gives a hydrocarbon (D), (D) when heated with HBr gives an isomer of (A). When (D) is treated with conc. H2SO4 and the product is diluted with water and distilled, (E) is obtained. Identify (A) to (E) and explain the reactions involved.

MEDIUM
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Dehydration of alcohols by concentrated H2SO4 takes place according to the following steps:

 The slowest and fastest steps in the above reaction are:

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Which of the following compounds gives the most stable carbonium ion on dehydration?

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n–butane on monobromination gives three isomers. The number of product(s) obtained when the major product is heated with KOH in CH3CH2OH is/are …..

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Optically active was found to have lost its optical activity after standing in water containing a few drops of acids, mainly due to the formation of

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The product that should be formed in the reaction is:

CH3-CC-CH3i H2,  lindlars catalyst(ii) Br2/CCl4Product

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How many structures of X is possible?

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Identify X and Y in the following reaction sequence