I: | In an organic compound, when inductive and electromeric effects operate in opposite directions, the inductive effect predominates. |
II: | Hyperconjugation is observed in o-xylene. |
Assertion (A): | Chlorine is an electron-withdrawing group, yet it exhibits ortho- and para-directing behavior in electrophilic aromatic substitution. |
Reason (R): | Inductive effect of chlorine destabilises the intermediate carbocation formed during the electrophilic substitution, however due to the more pronounced resonance effect, the halogen stabilises the carbocation at ortho and para positions. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |
A tertiary butyl carbocation is more stable than a secondary butyl carbocation because-
1. + R effect of groups
2. R effect of CH3 groups
3. Hyperconjugation
4. l effect of CH3 groups
The correct order with respect to –I effect of the substituents is:
(R = alkyl)
1. –NH2 > –OR < –F
2. –NR2 < –OR < –F
3. –NH2 > –OR > –F
4. –NR2 > –OR > –F
The most stable carbocation among the following is:
1. | 2. | ||
3. | 4. |
Hyperconjugation occurs among the following compounds:
1. | I only | 2. | II only |
3. | III only | 4. | I and III |
What is the correct sequence of acidity for the following compounds?
1. | CH3COOH > BrCH2COOH > ClCH2COOH > FCH2COOH |
2. | FCH2COOH > CH3COOH > BrCH2COOH > ClCH2COOH |
3. | BrCH2COOH > ClCH2COOH > FCH2COOH > CH3COOH |
4. | FCH2COOH > ClCH2COOH > BrCH2COOH > CH3COOH |
Which amongst the following is the most stable carbocation:
1. | 2. | ||
3. | 4. |
Polarisation of electrons in acrolein may be written as:
1.
2.
3.
4.