232318
Which among the following organic compounds do not have $(4 n+2)$ number of $\pi$ electrons (i) Phenanthrene (ii) Cyclooctatetraene (iii) Cyclopentadiene (iv) Cyclopentadienyl anion
1 (i) and (iv)
2 (ii) and (iii)
3 (i) and (ii)
4 (ii) and (iv)
Explanation:
The compound which is aromatic it must follow $(4 n+2) \pi$ electrons system. Compound (d) does not follow $(4 n+2) \pi$-electron system.
J and K CET-(2016)
GENERAL ORGANIC CHEMISTRY
232323
An aromatic compound among other things should have a $\pi$-electron cloud containing $(4 n+2) \pi$ electrons where $n$ can't be
1 $1 / 2$
2 3
3 2
4 1
Explanation:
An aromatic compound among other things should have a $\pi$-electron cloud containing only $(4 n+2) \pi$ electron where $\mathrm{n}$ is $0,1,2,3 \ldots \ldots$ in neither be $1 / 2$ because if we put $n=1 / 2$ Then $(4 \times 1 / \mathrm{x}+2) \pi=4 \pi \mathrm{e}^{-}$which is anti aromatic So, we can say that in $(4 n+2) \pi$ electron, $n=1 / 2$ is can not be use.
J and K CET-(2005)
GENERAL ORGANIC CHEMISTRY
232328
Pick out the wrong statement.
1 Toluene shows resonance
2 is non-aromatic
3 The hybrid state of carbon in carbonyl group is $\mathrm{sp}^{2}$
4 The hyperconjugative effect is known as no bond resonance
5 Dipole moment of vinyl chloride is less than that of methyl chloride
Explanation:
The wrong statement in the given option is (b) because (b) is a cyclohepta-trienyl action which is aromatic and given statement non-aromatic. It is aromatic because it has cyclic structure with $\mathrm{sp}^{2}$ hybridization and follow $(4 n+2) \pi$ electron system where $\mathrm{n}=0,1,2,3, \ldots$. It has $6 \pi$ so it is aromatic compound.
Kerala CEE-2007
GENERAL ORGANIC CHEMISTRY
232329
Which one of the following is a benzenoid aromatic compound?
1 Furan
2 Thiophene
3 Pyridine
4 Aniline
5 Cyclopentadienyl anion
Explanation:
Benzenoid-aromatic compound are referred to those compound which have at least one benzene ring. It may be one or more than one. It is aromatic but not contains any benzene ring so it is non-benzenoid. Compound a, b, c and e are non-benzenoid.
NEET Test Series from KOTA - 10 Papers In MS WORD
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GENERAL ORGANIC CHEMISTRY
232318
Which among the following organic compounds do not have $(4 n+2)$ number of $\pi$ electrons (i) Phenanthrene (ii) Cyclooctatetraene (iii) Cyclopentadiene (iv) Cyclopentadienyl anion
1 (i) and (iv)
2 (ii) and (iii)
3 (i) and (ii)
4 (ii) and (iv)
Explanation:
The compound which is aromatic it must follow $(4 n+2) \pi$ electrons system. Compound (d) does not follow $(4 n+2) \pi$-electron system.
J and K CET-(2016)
GENERAL ORGANIC CHEMISTRY
232323
An aromatic compound among other things should have a $\pi$-electron cloud containing $(4 n+2) \pi$ electrons where $n$ can't be
1 $1 / 2$
2 3
3 2
4 1
Explanation:
An aromatic compound among other things should have a $\pi$-electron cloud containing only $(4 n+2) \pi$ electron where $\mathrm{n}$ is $0,1,2,3 \ldots \ldots$ in neither be $1 / 2$ because if we put $n=1 / 2$ Then $(4 \times 1 / \mathrm{x}+2) \pi=4 \pi \mathrm{e}^{-}$which is anti aromatic So, we can say that in $(4 n+2) \pi$ electron, $n=1 / 2$ is can not be use.
J and K CET-(2005)
GENERAL ORGANIC CHEMISTRY
232328
Pick out the wrong statement.
1 Toluene shows resonance
2 is non-aromatic
3 The hybrid state of carbon in carbonyl group is $\mathrm{sp}^{2}$
4 The hyperconjugative effect is known as no bond resonance
5 Dipole moment of vinyl chloride is less than that of methyl chloride
Explanation:
The wrong statement in the given option is (b) because (b) is a cyclohepta-trienyl action which is aromatic and given statement non-aromatic. It is aromatic because it has cyclic structure with $\mathrm{sp}^{2}$ hybridization and follow $(4 n+2) \pi$ electron system where $\mathrm{n}=0,1,2,3, \ldots$. It has $6 \pi$ so it is aromatic compound.
Kerala CEE-2007
GENERAL ORGANIC CHEMISTRY
232329
Which one of the following is a benzenoid aromatic compound?
1 Furan
2 Thiophene
3 Pyridine
4 Aniline
5 Cyclopentadienyl anion
Explanation:
Benzenoid-aromatic compound are referred to those compound which have at least one benzene ring. It may be one or more than one. It is aromatic but not contains any benzene ring so it is non-benzenoid. Compound a, b, c and e are non-benzenoid.
232318
Which among the following organic compounds do not have $(4 n+2)$ number of $\pi$ electrons (i) Phenanthrene (ii) Cyclooctatetraene (iii) Cyclopentadiene (iv) Cyclopentadienyl anion
1 (i) and (iv)
2 (ii) and (iii)
3 (i) and (ii)
4 (ii) and (iv)
Explanation:
The compound which is aromatic it must follow $(4 n+2) \pi$ electrons system. Compound (d) does not follow $(4 n+2) \pi$-electron system.
J and K CET-(2016)
GENERAL ORGANIC CHEMISTRY
232323
An aromatic compound among other things should have a $\pi$-electron cloud containing $(4 n+2) \pi$ electrons where $n$ can't be
1 $1 / 2$
2 3
3 2
4 1
Explanation:
An aromatic compound among other things should have a $\pi$-electron cloud containing only $(4 n+2) \pi$ electron where $\mathrm{n}$ is $0,1,2,3 \ldots \ldots$ in neither be $1 / 2$ because if we put $n=1 / 2$ Then $(4 \times 1 / \mathrm{x}+2) \pi=4 \pi \mathrm{e}^{-}$which is anti aromatic So, we can say that in $(4 n+2) \pi$ electron, $n=1 / 2$ is can not be use.
J and K CET-(2005)
GENERAL ORGANIC CHEMISTRY
232328
Pick out the wrong statement.
1 Toluene shows resonance
2 is non-aromatic
3 The hybrid state of carbon in carbonyl group is $\mathrm{sp}^{2}$
4 The hyperconjugative effect is known as no bond resonance
5 Dipole moment of vinyl chloride is less than that of methyl chloride
Explanation:
The wrong statement in the given option is (b) because (b) is a cyclohepta-trienyl action which is aromatic and given statement non-aromatic. It is aromatic because it has cyclic structure with $\mathrm{sp}^{2}$ hybridization and follow $(4 n+2) \pi$ electron system where $\mathrm{n}=0,1,2,3, \ldots$. It has $6 \pi$ so it is aromatic compound.
Kerala CEE-2007
GENERAL ORGANIC CHEMISTRY
232329
Which one of the following is a benzenoid aromatic compound?
1 Furan
2 Thiophene
3 Pyridine
4 Aniline
5 Cyclopentadienyl anion
Explanation:
Benzenoid-aromatic compound are referred to those compound which have at least one benzene ring. It may be one or more than one. It is aromatic but not contains any benzene ring so it is non-benzenoid. Compound a, b, c and e are non-benzenoid.
232318
Which among the following organic compounds do not have $(4 n+2)$ number of $\pi$ electrons (i) Phenanthrene (ii) Cyclooctatetraene (iii) Cyclopentadiene (iv) Cyclopentadienyl anion
1 (i) and (iv)
2 (ii) and (iii)
3 (i) and (ii)
4 (ii) and (iv)
Explanation:
The compound which is aromatic it must follow $(4 n+2) \pi$ electrons system. Compound (d) does not follow $(4 n+2) \pi$-electron system.
J and K CET-(2016)
GENERAL ORGANIC CHEMISTRY
232323
An aromatic compound among other things should have a $\pi$-electron cloud containing $(4 n+2) \pi$ electrons where $n$ can't be
1 $1 / 2$
2 3
3 2
4 1
Explanation:
An aromatic compound among other things should have a $\pi$-electron cloud containing only $(4 n+2) \pi$ electron where $\mathrm{n}$ is $0,1,2,3 \ldots \ldots$ in neither be $1 / 2$ because if we put $n=1 / 2$ Then $(4 \times 1 / \mathrm{x}+2) \pi=4 \pi \mathrm{e}^{-}$which is anti aromatic So, we can say that in $(4 n+2) \pi$ electron, $n=1 / 2$ is can not be use.
J and K CET-(2005)
GENERAL ORGANIC CHEMISTRY
232328
Pick out the wrong statement.
1 Toluene shows resonance
2 is non-aromatic
3 The hybrid state of carbon in carbonyl group is $\mathrm{sp}^{2}$
4 The hyperconjugative effect is known as no bond resonance
5 Dipole moment of vinyl chloride is less than that of methyl chloride
Explanation:
The wrong statement in the given option is (b) because (b) is a cyclohepta-trienyl action which is aromatic and given statement non-aromatic. It is aromatic because it has cyclic structure with $\mathrm{sp}^{2}$ hybridization and follow $(4 n+2) \pi$ electron system where $\mathrm{n}=0,1,2,3, \ldots$. It has $6 \pi$ so it is aromatic compound.
Kerala CEE-2007
GENERAL ORGANIC CHEMISTRY
232329
Which one of the following is a benzenoid aromatic compound?
1 Furan
2 Thiophene
3 Pyridine
4 Aniline
5 Cyclopentadienyl anion
Explanation:
Benzenoid-aromatic compound are referred to those compound which have at least one benzene ring. It may be one or more than one. It is aromatic but not contains any benzene ring so it is non-benzenoid. Compound a, b, c and e are non-benzenoid.