Assertion (A): | chlorine is an electron-withdrawing group, yet it is ortho-, para- directing in electrophilic aromatic substitution reactions. |
Reason (R): | Halogen atom is a ring deactivator. |
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. |
Given below are two statements:
Assertion (A): | Vinyl halides do not undergo nucleophilic substitution easily. |
Reason (R): | Even though the intermediate carbocation is stabilized by loosely held p-electrons, the cleavage is difficult because of strong bonding. |
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. | Both (A) and (R) are false. |
Select the correct option based on statements below:
Assertion (A): | Nitration of chlorobenzene leads to the formation of m-nitrochlorobenzene. |
Reason (R): | —NO2 group is an m-directing group. |
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. |
Select the correct option based on statements below:
Assertion (A): | Hydrolysis of (-)-2-bromooctane proceeds with an inversion of configuration. |
Reason (R): | This reaction proceeds through the formation of a carbocation. |
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. |
Given below are two statements:
Assertion (A): | It is difficult to replace chlorine by -OH in chlorobenzene in comparison to that in chloroethane. |
Reason (R): | Chlorine carbon (C—Cl) bond in chlorobenzene has a partial double bond character due to resonance. |
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. |
Select the correct option based on statements below:
Assertion (A): | In monohaloarenes, further electrophilic substitution occurs at ortho and para positions. |
Reason (R): | The halogen atom is a ring deactivator. |
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. |
Select the correct option based on statements below:
Assertion (A): | The presence of a nitro group at ortho or para position increases the reactivity of haloarenes towards nucleophilic substitution. |
Reason (R): | The nitro group, being an electron-withdrawing group, decreases the electron density over the benzene ring. |
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. |
Given below are two statements:
Assertion (A): | tert-butyl bromide undergoes Wurtz reaction to give 2,2,3,3-tetramethylbutane. |
Reason (R): | In Wurtz reaction, alkyl halides react with sodium in dry ether to give hydrocarbon containing double the number of carbon atoms present in the halide. |
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. |
Select the correct option based on statements below:
Assertion (A): | KCN reacts with methyl chloride to give methyl isocyanide. |
Reason (R): | \(CN^-\) is an ambident nucleophile. |
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. |
Select the correct option based on statements below:
Assertion (A): | The boiling points of alkyl halides decrease in the order RI> RBr > RCl > RF |
Reason (R): | The boiling points of alkyl chlorides, bromides, and iodides are considerably higher than those of the hydrocarbons of comparable molecular mass. |
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. |