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प्रश्न
Draw the cis and trans structures of hex-2-ene. Which isomer will have higher b.p. and why?
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उत्तर
Hex-2-ene is represented as:
\[\ce{CH3 - CH = CH - CH2 - CH2 - CH3}\]
Geometrical isomers of hex-2-ene are:
\[\begin{array}{cc}
\phantom{.............}\ce{H3C}\phantom{.........}\ce{CH2 - CH2 - CH3}\\
\backslash\phantom{.......}/\\
\ce{C = C}\\
/\phantom{.......}\backslash\\
\ce{H}\phantom{.........}\ce{H}\end{array}\]
cis-isomer
\[\begin{array}{cc}
\phantom{.}\ce{H3C}\phantom{......}\ce{H}\\
\backslash\phantom{.......}/\\
\ce{C = C}\\
/\phantom{.......}\backslash\\
\phantom{..............}\ce{H}\phantom{.......}\ce{CH2 - CH2 - CH3}\end{array}\]
trans-isomer
The dipole moment of cis-compound is a sum of the dipole moments of C–CH3 and C–CH2CH2CH3 bonds acting in the same direction.
The dipole moment of trans-compound is the resultant of the dipole moments of C–CH3 and C–CH2CH2CH3 bonds acting in opposite directions.
Hence, cis-isomer is more polar than trans-isomer. The higher the polarity, the greater is the intermolecular dipole-dipole interaction and the higher will be the boiling point. Hence, cis-isomer will have a higher boiling point than trans-isomer.
संबंधित प्रश्न
Write IUPAC name of the product obtained by the ozonolysis of the following compound:
3,4-Dimethyl-hept-3-ene
What effect does branching of an alkane chain has on its boiling point?
What is the relationship between the members of following pairs of structures? Are they structural or geometrical isomers or resonance contributors?
\[\begin{array}{cc}
\ce{D}\phantom{......}\ce{H}\\
\backslash\phantom{......}/\\
\ce{C = C}\\
\phantom{...}/\phantom{......}\backslash\phantom{...}\\\ce{H}\phantom{.......}\ce{D}
\end{array}\]
\[\begin{array}{cc}
\ce{D}\phantom{......}\ce{D}\\
\backslash\phantom{......}/\\
\ce{C = C}\\
\phantom{...}/\phantom{......}\backslash\phantom{...}\\\ce{H}\phantom{.......}\ce{H}\end{array}\]
Find out the type of isomerism exhibited by the following pair.
\[\begin{array}{cc}
\ce{CH3 - CH - CH2 - CH3 and CH3 - CH2 - O - CH2 - CH3}\\|\phantom{...........................................}\\
\ce{OH}\phantom{.........................................}\end{array}\]
Find out the type of isomerism exhibited by the following pair.
Find out the type of isomerism exhibited by the following pair.
Molecular formula of the functional isomer of methyl formate is ____________.
What type(s) of isomerism is(are) shown by [Co(NH3)4Br2]Cl?
But-1-ene and But-2-ene are examples of ____________.
The type of isomerism possible in 2-butene is ____________.
What is the relationship between the members of following pairs of structures? Are they structural or geometrical isomers or resonance contributors?
Which of the following pairs are position isomers?
| I. | \[\begin{array}{cc} \phantom{.......................}\ce{O}\\ \phantom{.......................}||\\ \ce{CH3 - CH2 - CH2 - CH2 - C - H} \end{array}\] |
| II. | \[\begin{array}{cc} \phantom{.................}\ce{O}\\ \phantom{.................}||\\ \ce{CH3 - CH2 - CH2 - C - H} \end{array}\] |
| III. | \[\begin{array}{cc} \ce{CH3 - CH2 - C - CH2 - CH3}\\ \phantom{}||\\ \phantom{}\ce{O} \end{array}\] |
| IV. | \[\begin{array}{cc} \ce{CH3 - CH - CH2 - C - H}\\ \phantom{...}|\phantom{............}||\phantom{}\\ \phantom{...}\ce{CH3}\phantom{.........}\ce{O}\phantom{} \end{array}\] |
(i) I and II
(ii) II and III
(iii) II and IV
(iv) III and IV
Which of the following pairs are not functional group isomers?
| I. | \[\begin{array}{cc} \phantom{.......................}\ce{O}\\ \phantom{.......................}||\\ \ce{CH3 - CH2 - CH2 - CH2 - C - H} \end{array}\] |
| II. | \[\begin{array}{cc} \phantom{.................}\ce{O}\\ \phantom{.................}||\\ \ce{CH3 - CH2 - CH2 - C - H} \end{array}\] |
| III. | \[\begin{array}{cc} \ce{CH3 - CH2 - C - CH2 - CH3}\\ \phantom{}||\\ \phantom{}\ce{O} \end{array}\] |
| IV. | \[\begin{array}{cc} \ce{CH3 - CH - CH2 - C - H}\\ \phantom{...}|\phantom{............}||\phantom{}\\ \phantom{...}\ce{CH3}\phantom{.........}\ce{O}\phantom{} \end{array}\] |
(i) II and III
(ii) II and IV
(iii) I and IV
(iv) I and II
Consider structures I to VII and answer the question:
| I. | CH3 – CH2 – CH2 – CH2 – OH |
| II. | \[\begin{array}{cc} \ce{CH3 - CH2 - CH - CH3}\\ \phantom{.....}|\\ \phantom{.......}\ce{OH} \end{array}\] |
| III. | \[\begin{array}{cc} \phantom{...}\ce{CH3}\\ \phantom{}|\\ \ce{CH3 - C - CH3}\\ \phantom{}|\\ \phantom{..}\ce{OH} \end{array}\] |
| IV. | \[\begin{array}{cc} \ce{CH3 - CH - CH2 - OH}\\ |\phantom{........}\\ \ce{CH3}\phantom{......} \end{array}\] |
| V. | CH3 – CH2 – O – CH2 – CH3 |
| VI. | CH3 – O – CH2 – CH2 – CH3 |
| VII. | \[\begin{array}{cc} \ce{CH3 - O - CH - CH3}\\ \phantom{...}|\\ \phantom{......}\ce{CH3} \end{array}\] |
Identify the pairs of compounds that represents position isomerism.
Consider structures I to VII and answer the question:
| I. | CH3 – CH2 – CH2 – CH2 – OH |
| II. | \[\begin{array}{cc} \ce{CH3 - CH2 - CH - CH3}\\ \phantom{.....}|\\ \phantom{.......}\ce{OH} \end{array}\] |
| III. | \[\begin{array}{cc} \phantom{...}\ce{CH3}\\ \phantom{}|\\ \ce{CH3 - C - CH3}\\ \phantom{}|\\ \phantom{..}\ce{OH} \end{array}\] |
| IV. | \[\begin{array}{cc} \ce{CH3 - CH - CH2 - OH}\\ |\phantom{........}\\ \ce{CH3}\phantom{......} \end{array}\] |
| V. | CH3 – CH2 – O – CH2 – CH3 |
| VI. | CH3 – O – CH2 – CH2 – CH3 |
| VII. | \[\begin{array}{cc} \ce{CH3 - O - CH - CH3}\\ \phantom{...}|\\ \phantom{......}\ce{CH3} \end{array}\] |
Identify the pairs of compounds that represents chain isomerism.
Assertion (A): The compound cyclooctane has the following structural formula: 
It is cyclic and has conjugated 8π-electron system but it is not an aromatic compound.
Reason (R): (4n + 2)π electrons rule does not hold good and ring is not planar.
Tautomerism is exhibited by ______.
Ether and alcohol are ______.
The compound which shows metamerism is ______
Which type of isomerism can not be shown by benzaldoxime?
Acetamide is isomer of ______.
Which one of the following pairs are called position isomers?
How many structural isomers possible of the molecular formula C3H6O (excluding enol form)?
Which of the following reactions will not produce a racemic product?
The number of geometrical isomers from [Co(NH3)3(NO2)3] is ______.
Which of the following pairs of compounds is an example of position isomerism?
