318008
Assertion : Trans-Pent-2-ene is polar but transbut-2-ene is non-polar. Reason : The polarity of cis-isomer is more than trans-isomer, which is either non-polar or less polar.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
In trans-pent-2-ene, the vector sum of all polar bonds does not cancel out to zero due to unsymmetrical distribution of polar bonds. Thus there is a net dipole moment, making the molecule polar. On the other hand, in trans-but-2-ene, the vector sum of polar bonds is zero due to the symmetrical arrangement of polar bonds that cancel each other out. This results in a nonpolar molecule with no net dipole moment. In general cis alkenes is more polar than trans alkenes but it's not the correct explanation. So, option (2) is correct.
CHXI13:HYDROCARBONS
318009
The incorrect statement regarding the geometrical isomers of 2-butene is
1 cis-2-butene and trans-2-butene are not interconvertible at room temperature
2 cis-2-butene has less dipole moment than trans-2-butene.
3 trans-2-butene is more stable than cis-2-butene
4 cis-2-butene and trans-2-butene are stereoisomers.
Explanation:
cis-2-butene has more dipole moment than trans-2-butene \({\mathrm{(\mu=0)}}\). So, the correct option is (2).
JEE Main - 2024
CHXI13:HYDROCARBONS
318010
Assertion : But-2-ene shows geometrical isomerism but but-1-ene does not show. Reason : Geometrical isomerism arises due to the restricted rotation of the double bond.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
In but-1-ene, the carbon atom linked by double bond is attached with two hydrogen atoms (similar groups) and thus, it does not show geometrical isomerism. So, option (2) is correct.
CHXI13:HYDROCARBONS
318011
Which of the following pairs represent positional isomerism?
1 But-1-ene and but-2-ene
2 But-1-ene and 2-methylprop-1-ene
3 Prop-2-en-1-ol and methoxyethene
4 n-Butane and 2-methylpropane
Explanation:
Position isomerism: But-1-ene and but -2 - ene Chain isomerism: But-1-ene and 2-methylprop-1-ene, n-butane and 2-methylpropane Functional isomerism: Prop-2-en-1-ol and methoxyethene
318008
Assertion : Trans-Pent-2-ene is polar but transbut-2-ene is non-polar. Reason : The polarity of cis-isomer is more than trans-isomer, which is either non-polar or less polar.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
In trans-pent-2-ene, the vector sum of all polar bonds does not cancel out to zero due to unsymmetrical distribution of polar bonds. Thus there is a net dipole moment, making the molecule polar. On the other hand, in trans-but-2-ene, the vector sum of polar bonds is zero due to the symmetrical arrangement of polar bonds that cancel each other out. This results in a nonpolar molecule with no net dipole moment. In general cis alkenes is more polar than trans alkenes but it's not the correct explanation. So, option (2) is correct.
CHXI13:HYDROCARBONS
318009
The incorrect statement regarding the geometrical isomers of 2-butene is
1 cis-2-butene and trans-2-butene are not interconvertible at room temperature
2 cis-2-butene has less dipole moment than trans-2-butene.
3 trans-2-butene is more stable than cis-2-butene
4 cis-2-butene and trans-2-butene are stereoisomers.
Explanation:
cis-2-butene has more dipole moment than trans-2-butene \({\mathrm{(\mu=0)}}\). So, the correct option is (2).
JEE Main - 2024
CHXI13:HYDROCARBONS
318010
Assertion : But-2-ene shows geometrical isomerism but but-1-ene does not show. Reason : Geometrical isomerism arises due to the restricted rotation of the double bond.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
In but-1-ene, the carbon atom linked by double bond is attached with two hydrogen atoms (similar groups) and thus, it does not show geometrical isomerism. So, option (2) is correct.
CHXI13:HYDROCARBONS
318011
Which of the following pairs represent positional isomerism?
1 But-1-ene and but-2-ene
2 But-1-ene and 2-methylprop-1-ene
3 Prop-2-en-1-ol and methoxyethene
4 n-Butane and 2-methylpropane
Explanation:
Position isomerism: But-1-ene and but -2 - ene Chain isomerism: But-1-ene and 2-methylprop-1-ene, n-butane and 2-methylpropane Functional isomerism: Prop-2-en-1-ol and methoxyethene
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CHXI13:HYDROCARBONS
318008
Assertion : Trans-Pent-2-ene is polar but transbut-2-ene is non-polar. Reason : The polarity of cis-isomer is more than trans-isomer, which is either non-polar or less polar.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
In trans-pent-2-ene, the vector sum of all polar bonds does not cancel out to zero due to unsymmetrical distribution of polar bonds. Thus there is a net dipole moment, making the molecule polar. On the other hand, in trans-but-2-ene, the vector sum of polar bonds is zero due to the symmetrical arrangement of polar bonds that cancel each other out. This results in a nonpolar molecule with no net dipole moment. In general cis alkenes is more polar than trans alkenes but it's not the correct explanation. So, option (2) is correct.
CHXI13:HYDROCARBONS
318009
The incorrect statement regarding the geometrical isomers of 2-butene is
1 cis-2-butene and trans-2-butene are not interconvertible at room temperature
2 cis-2-butene has less dipole moment than trans-2-butene.
3 trans-2-butene is more stable than cis-2-butene
4 cis-2-butene and trans-2-butene are stereoisomers.
Explanation:
cis-2-butene has more dipole moment than trans-2-butene \({\mathrm{(\mu=0)}}\). So, the correct option is (2).
JEE Main - 2024
CHXI13:HYDROCARBONS
318010
Assertion : But-2-ene shows geometrical isomerism but but-1-ene does not show. Reason : Geometrical isomerism arises due to the restricted rotation of the double bond.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
In but-1-ene, the carbon atom linked by double bond is attached with two hydrogen atoms (similar groups) and thus, it does not show geometrical isomerism. So, option (2) is correct.
CHXI13:HYDROCARBONS
318011
Which of the following pairs represent positional isomerism?
1 But-1-ene and but-2-ene
2 But-1-ene and 2-methylprop-1-ene
3 Prop-2-en-1-ol and methoxyethene
4 n-Butane and 2-methylpropane
Explanation:
Position isomerism: But-1-ene and but -2 - ene Chain isomerism: But-1-ene and 2-methylprop-1-ene, n-butane and 2-methylpropane Functional isomerism: Prop-2-en-1-ol and methoxyethene
318008
Assertion : Trans-Pent-2-ene is polar but transbut-2-ene is non-polar. Reason : The polarity of cis-isomer is more than trans-isomer, which is either non-polar or less polar.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
In trans-pent-2-ene, the vector sum of all polar bonds does not cancel out to zero due to unsymmetrical distribution of polar bonds. Thus there is a net dipole moment, making the molecule polar. On the other hand, in trans-but-2-ene, the vector sum of polar bonds is zero due to the symmetrical arrangement of polar bonds that cancel each other out. This results in a nonpolar molecule with no net dipole moment. In general cis alkenes is more polar than trans alkenes but it's not the correct explanation. So, option (2) is correct.
CHXI13:HYDROCARBONS
318009
The incorrect statement regarding the geometrical isomers of 2-butene is
1 cis-2-butene and trans-2-butene are not interconvertible at room temperature
2 cis-2-butene has less dipole moment than trans-2-butene.
3 trans-2-butene is more stable than cis-2-butene
4 cis-2-butene and trans-2-butene are stereoisomers.
Explanation:
cis-2-butene has more dipole moment than trans-2-butene \({\mathrm{(\mu=0)}}\). So, the correct option is (2).
JEE Main - 2024
CHXI13:HYDROCARBONS
318010
Assertion : But-2-ene shows geometrical isomerism but but-1-ene does not show. Reason : Geometrical isomerism arises due to the restricted rotation of the double bond.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
In but-1-ene, the carbon atom linked by double bond is attached with two hydrogen atoms (similar groups) and thus, it does not show geometrical isomerism. So, option (2) is correct.
CHXI13:HYDROCARBONS
318011
Which of the following pairs represent positional isomerism?
1 But-1-ene and but-2-ene
2 But-1-ene and 2-methylprop-1-ene
3 Prop-2-en-1-ol and methoxyethene
4 n-Butane and 2-methylpropane
Explanation:
Position isomerism: But-1-ene and but -2 - ene Chain isomerism: But-1-ene and 2-methylprop-1-ene, n-butane and 2-methylpropane Functional isomerism: Prop-2-en-1-ol and methoxyethene
