231276
The correct order of acid character of the following compounds is :
1 I $>$ II $>$ III $>$ IV
2 III $>$ II $>$ I $>$ IV
3 II $>$ III $>$ IV $>$ I
4 IV $>$ III $>$ II $>$ I
Explanation:
The most acidic compound is p-nitro-benzoic acid. Phenol is least acidic among them. Carboxylic acid is most acidic because the resonating structures in which (-ve) charge is effectively delocalised between two more electronegative oxygen atoms. Hence, carboxylic acid are more acidic than phenol. Acidity of carboxylic acid $\alpha-\mathrm{R}>-\mathrm{H}>-\mathrm{I}$ $1 / \alpha+\mathrm{R}>+\mathrm{H}>+\mathrm{I}$ The correct order will be - So, option (c) is correct.
JEE Main 25.02.2021
GENERAL ORGANIC CHEMISTRY
231277
Consider the following compounds: What is the correct order of acidity of the above compounds?
1 I $<$ II $<$ III
2 III $<$ I $<$ II
3 II $<$ I $<$ III
4 III $<$ II $<$ I
Explanation:
o-hydroxybenzoic acid is most acidic because after losing $\mathrm{H}^{+}$the $\mathrm{COO}^{-}$is stabilised by $\mathrm{H}$-bonding with $-\mathrm{OH}$ group. p-hydroxy benzoic acid is least acidic because of $+\mathrm{m}$ effect if $-\mathrm{OH}$ group at para position decreases it's acidic character. $\mathrm{m}$ - hydroxyl benzoic acid is more acidic than benzoic acid. So, order will be:-
SCRA-2010
GENERAL ORGANIC CHEMISTRY
231280
Assertion: Phenol is more acidic than m-methoxy phenol. Reason: $-\mathrm{OCH}_{3}$ shows $+\mathrm{I}$ effect.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
(D):
AIIMS 26 May 2019 (Evening)
GENERAL ORGANIC CHEMISTRY
231281
For diazonium ions the order of reactivity towards diazo-coupling with phenol in the presence of dilute $\mathrm{NaOH}$ is:
1 I $<$ IV $<$ II $<$ III
2 I $<$ III $<$ IV $<$ II
3 III $<$ I $<$ II $<$ IV
4 III $<$ I $<$ IV $<$ II
Explanation:
(A): Diazonium ion acts as electrophile in coupling reaction, greater the electron withdrawing power, higher electrophilicity. I < IV < II < III
231276
The correct order of acid character of the following compounds is :
1 I $>$ II $>$ III $>$ IV
2 III $>$ II $>$ I $>$ IV
3 II $>$ III $>$ IV $>$ I
4 IV $>$ III $>$ II $>$ I
Explanation:
The most acidic compound is p-nitro-benzoic acid. Phenol is least acidic among them. Carboxylic acid is most acidic because the resonating structures in which (-ve) charge is effectively delocalised between two more electronegative oxygen atoms. Hence, carboxylic acid are more acidic than phenol. Acidity of carboxylic acid $\alpha-\mathrm{R}>-\mathrm{H}>-\mathrm{I}$ $1 / \alpha+\mathrm{R}>+\mathrm{H}>+\mathrm{I}$ The correct order will be - So, option (c) is correct.
JEE Main 25.02.2021
GENERAL ORGANIC CHEMISTRY
231277
Consider the following compounds: What is the correct order of acidity of the above compounds?
1 I $<$ II $<$ III
2 III $<$ I $<$ II
3 II $<$ I $<$ III
4 III $<$ II $<$ I
Explanation:
o-hydroxybenzoic acid is most acidic because after losing $\mathrm{H}^{+}$the $\mathrm{COO}^{-}$is stabilised by $\mathrm{H}$-bonding with $-\mathrm{OH}$ group. p-hydroxy benzoic acid is least acidic because of $+\mathrm{m}$ effect if $-\mathrm{OH}$ group at para position decreases it's acidic character. $\mathrm{m}$ - hydroxyl benzoic acid is more acidic than benzoic acid. So, order will be:-
SCRA-2010
GENERAL ORGANIC CHEMISTRY
231280
Assertion: Phenol is more acidic than m-methoxy phenol. Reason: $-\mathrm{OCH}_{3}$ shows $+\mathrm{I}$ effect.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
(D):
AIIMS 26 May 2019 (Evening)
GENERAL ORGANIC CHEMISTRY
231281
For diazonium ions the order of reactivity towards diazo-coupling with phenol in the presence of dilute $\mathrm{NaOH}$ is:
1 I $<$ IV $<$ II $<$ III
2 I $<$ III $<$ IV $<$ II
3 III $<$ I $<$ II $<$ IV
4 III $<$ I $<$ IV $<$ II
Explanation:
(A): Diazonium ion acts as electrophile in coupling reaction, greater the electron withdrawing power, higher electrophilicity. I < IV < II < III
231276
The correct order of acid character of the following compounds is :
1 I $>$ II $>$ III $>$ IV
2 III $>$ II $>$ I $>$ IV
3 II $>$ III $>$ IV $>$ I
4 IV $>$ III $>$ II $>$ I
Explanation:
The most acidic compound is p-nitro-benzoic acid. Phenol is least acidic among them. Carboxylic acid is most acidic because the resonating structures in which (-ve) charge is effectively delocalised between two more electronegative oxygen atoms. Hence, carboxylic acid are more acidic than phenol. Acidity of carboxylic acid $\alpha-\mathrm{R}>-\mathrm{H}>-\mathrm{I}$ $1 / \alpha+\mathrm{R}>+\mathrm{H}>+\mathrm{I}$ The correct order will be - So, option (c) is correct.
JEE Main 25.02.2021
GENERAL ORGANIC CHEMISTRY
231277
Consider the following compounds: What is the correct order of acidity of the above compounds?
1 I $<$ II $<$ III
2 III $<$ I $<$ II
3 II $<$ I $<$ III
4 III $<$ II $<$ I
Explanation:
o-hydroxybenzoic acid is most acidic because after losing $\mathrm{H}^{+}$the $\mathrm{COO}^{-}$is stabilised by $\mathrm{H}$-bonding with $-\mathrm{OH}$ group. p-hydroxy benzoic acid is least acidic because of $+\mathrm{m}$ effect if $-\mathrm{OH}$ group at para position decreases it's acidic character. $\mathrm{m}$ - hydroxyl benzoic acid is more acidic than benzoic acid. So, order will be:-
SCRA-2010
GENERAL ORGANIC CHEMISTRY
231280
Assertion: Phenol is more acidic than m-methoxy phenol. Reason: $-\mathrm{OCH}_{3}$ shows $+\mathrm{I}$ effect.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
(D):
AIIMS 26 May 2019 (Evening)
GENERAL ORGANIC CHEMISTRY
231281
For diazonium ions the order of reactivity towards diazo-coupling with phenol in the presence of dilute $\mathrm{NaOH}$ is:
1 I $<$ IV $<$ II $<$ III
2 I $<$ III $<$ IV $<$ II
3 III $<$ I $<$ II $<$ IV
4 III $<$ I $<$ IV $<$ II
Explanation:
(A): Diazonium ion acts as electrophile in coupling reaction, greater the electron withdrawing power, higher electrophilicity. I < IV < II < III
231276
The correct order of acid character of the following compounds is :
1 I $>$ II $>$ III $>$ IV
2 III $>$ II $>$ I $>$ IV
3 II $>$ III $>$ IV $>$ I
4 IV $>$ III $>$ II $>$ I
Explanation:
The most acidic compound is p-nitro-benzoic acid. Phenol is least acidic among them. Carboxylic acid is most acidic because the resonating structures in which (-ve) charge is effectively delocalised between two more electronegative oxygen atoms. Hence, carboxylic acid are more acidic than phenol. Acidity of carboxylic acid $\alpha-\mathrm{R}>-\mathrm{H}>-\mathrm{I}$ $1 / \alpha+\mathrm{R}>+\mathrm{H}>+\mathrm{I}$ The correct order will be - So, option (c) is correct.
JEE Main 25.02.2021
GENERAL ORGANIC CHEMISTRY
231277
Consider the following compounds: What is the correct order of acidity of the above compounds?
1 I $<$ II $<$ III
2 III $<$ I $<$ II
3 II $<$ I $<$ III
4 III $<$ II $<$ I
Explanation:
o-hydroxybenzoic acid is most acidic because after losing $\mathrm{H}^{+}$the $\mathrm{COO}^{-}$is stabilised by $\mathrm{H}$-bonding with $-\mathrm{OH}$ group. p-hydroxy benzoic acid is least acidic because of $+\mathrm{m}$ effect if $-\mathrm{OH}$ group at para position decreases it's acidic character. $\mathrm{m}$ - hydroxyl benzoic acid is more acidic than benzoic acid. So, order will be:-
SCRA-2010
GENERAL ORGANIC CHEMISTRY
231280
Assertion: Phenol is more acidic than m-methoxy phenol. Reason: $-\mathrm{OCH}_{3}$ shows $+\mathrm{I}$ effect.
1 If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
2 If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
3 If Assertion is correct but Reason is incorrect.
4 If both the Assertion and Reason are incorrect.
Explanation:
(D):
AIIMS 26 May 2019 (Evening)
GENERAL ORGANIC CHEMISTRY
231281
For diazonium ions the order of reactivity towards diazo-coupling with phenol in the presence of dilute $\mathrm{NaOH}$ is:
1 I $<$ IV $<$ II $<$ III
2 I $<$ III $<$ IV $<$ II
3 III $<$ I $<$ II $<$ IV
4 III $<$ I $<$ IV $<$ II
Explanation:
(A): Diazonium ion acts as electrophile in coupling reaction, greater the electron withdrawing power, higher electrophilicity. I < IV < II < III