CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317627
Assertion : Molecules that are not superimposable on their mirror images are chiral. Reason : All chiral molecules have chiral centres.
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:
Molecules that are not superimposable on their mirror images are asymmetric and hence chiral. Such molecules are known as enantiomers. These molecules when placed on top of one another will not give the same molecule hence they are chiral. A molecule can be chiral even if it does not have a stereocenter. A molecule's chirality depends entirely on whether it is asymmetrical. Example, Biphenyls do not have a chiral carbon but they cannot rotate freely due to steric crowding. Hence, they are asymmetrical. Suitably substituted allenes (2,3-pentadiene) and biphenyls are optically active although they are dissymmetric, i.e. do not have asymmetric carbon atom. So, the option (3) is correct.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317628
In the representation of specific rotation \(\left( {{\rm{[\alpha ]}}_{\rm{D}}^{{\rm{2}}{{\rm{5}}^{\rm{o}}}{\rm{C}}}} \right){\rm{,}}\) 'D' indicates
1 Dextro
2 Configuration of - \(\mathrm{OH}\) group
3 Configuration of \(-\mathrm{NH}_{2}\) group
4 Wave length of light
Explanation:
Conceptual Questions
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317629
\({\rm{( \pm )}}\) lactic acid is optically inactive due to
1 Internal compensation
2 External compensation
3 Presence of plane of symmetry
4 Absence of asymmetric carbon
Explanation:
Racemic mixture \(\left( {\rm{ \pm }} \right)\) is optically inactive due to external compensation.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317630
A compound has 3 chiral carbon atoms. The number of possible optical isomers it can have
1 3
2 3
3 8
4 4
Explanation:
The number of possible optical isomers \(=2^{n}\) (where, ' \(\mathrm{n}\) ' is the number of chiral C - atoms) \(=2^{3}=8\).
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317627
Assertion : Molecules that are not superimposable on their mirror images are chiral. Reason : All chiral molecules have chiral centres.
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:
Molecules that are not superimposable on their mirror images are asymmetric and hence chiral. Such molecules are known as enantiomers. These molecules when placed on top of one another will not give the same molecule hence they are chiral. A molecule can be chiral even if it does not have a stereocenter. A molecule's chirality depends entirely on whether it is asymmetrical. Example, Biphenyls do not have a chiral carbon but they cannot rotate freely due to steric crowding. Hence, they are asymmetrical. Suitably substituted allenes (2,3-pentadiene) and biphenyls are optically active although they are dissymmetric, i.e. do not have asymmetric carbon atom. So, the option (3) is correct.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317628
In the representation of specific rotation \(\left( {{\rm{[\alpha ]}}_{\rm{D}}^{{\rm{2}}{{\rm{5}}^{\rm{o}}}{\rm{C}}}} \right){\rm{,}}\) 'D' indicates
1 Dextro
2 Configuration of - \(\mathrm{OH}\) group
3 Configuration of \(-\mathrm{NH}_{2}\) group
4 Wave length of light
Explanation:
Conceptual Questions
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317629
\({\rm{( \pm )}}\) lactic acid is optically inactive due to
1 Internal compensation
2 External compensation
3 Presence of plane of symmetry
4 Absence of asymmetric carbon
Explanation:
Racemic mixture \(\left( {\rm{ \pm }} \right)\) is optically inactive due to external compensation.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317630
A compound has 3 chiral carbon atoms. The number of possible optical isomers it can have
1 3
2 3
3 8
4 4
Explanation:
The number of possible optical isomers \(=2^{n}\) (where, ' \(\mathrm{n}\) ' is the number of chiral C - atoms) \(=2^{3}=8\).
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317627
Assertion : Molecules that are not superimposable on their mirror images are chiral. Reason : All chiral molecules have chiral centres.
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:
Molecules that are not superimposable on their mirror images are asymmetric and hence chiral. Such molecules are known as enantiomers. These molecules when placed on top of one another will not give the same molecule hence they are chiral. A molecule can be chiral even if it does not have a stereocenter. A molecule's chirality depends entirely on whether it is asymmetrical. Example, Biphenyls do not have a chiral carbon but they cannot rotate freely due to steric crowding. Hence, they are asymmetrical. Suitably substituted allenes (2,3-pentadiene) and biphenyls are optically active although they are dissymmetric, i.e. do not have asymmetric carbon atom. So, the option (3) is correct.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317628
In the representation of specific rotation \(\left( {{\rm{[\alpha ]}}_{\rm{D}}^{{\rm{2}}{{\rm{5}}^{\rm{o}}}{\rm{C}}}} \right){\rm{,}}\) 'D' indicates
1 Dextro
2 Configuration of - \(\mathrm{OH}\) group
3 Configuration of \(-\mathrm{NH}_{2}\) group
4 Wave length of light
Explanation:
Conceptual Questions
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317629
\({\rm{( \pm )}}\) lactic acid is optically inactive due to
1 Internal compensation
2 External compensation
3 Presence of plane of symmetry
4 Absence of asymmetric carbon
Explanation:
Racemic mixture \(\left( {\rm{ \pm }} \right)\) is optically inactive due to external compensation.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317630
A compound has 3 chiral carbon atoms. The number of possible optical isomers it can have
1 3
2 3
3 8
4 4
Explanation:
The number of possible optical isomers \(=2^{n}\) (where, ' \(\mathrm{n}\) ' is the number of chiral C - atoms) \(=2^{3}=8\).
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317627
Assertion : Molecules that are not superimposable on their mirror images are chiral. Reason : All chiral molecules have chiral centres.
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:
Molecules that are not superimposable on their mirror images are asymmetric and hence chiral. Such molecules are known as enantiomers. These molecules when placed on top of one another will not give the same molecule hence they are chiral. A molecule can be chiral even if it does not have a stereocenter. A molecule's chirality depends entirely on whether it is asymmetrical. Example, Biphenyls do not have a chiral carbon but they cannot rotate freely due to steric crowding. Hence, they are asymmetrical. Suitably substituted allenes (2,3-pentadiene) and biphenyls are optically active although they are dissymmetric, i.e. do not have asymmetric carbon atom. So, the option (3) is correct.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317628
In the representation of specific rotation \(\left( {{\rm{[\alpha ]}}_{\rm{D}}^{{\rm{2}}{{\rm{5}}^{\rm{o}}}{\rm{C}}}} \right){\rm{,}}\) 'D' indicates
1 Dextro
2 Configuration of - \(\mathrm{OH}\) group
3 Configuration of \(-\mathrm{NH}_{2}\) group
4 Wave length of light
Explanation:
Conceptual Questions
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317629
\({\rm{( \pm )}}\) lactic acid is optically inactive due to
1 Internal compensation
2 External compensation
3 Presence of plane of symmetry
4 Absence of asymmetric carbon
Explanation:
Racemic mixture \(\left( {\rm{ \pm }} \right)\) is optically inactive due to external compensation.
CHXI12:ORGANIC CHEMISTRY SOME BASIC PRINCIPLES AND TECHNIQUES
317630
A compound has 3 chiral carbon atoms. The number of possible optical isomers it can have
1 3
2 3
3 8
4 4
Explanation:
The number of possible optical isomers \(=2^{n}\) (where, ' \(\mathrm{n}\) ' is the number of chiral C - atoms) \(=2^{3}=8\).
