Directive Influence of Substituents

Q. Which of the following is an electrophile?

1. H₂O
2. NH₃
3. AlCl₃
4. C₂H₅NH₂

Q.

Which among $\mathrm{MeX},{\mathrm{RCH}}_2\mathrm{X},{\mathrm{R}}_2\mathrm{CHX},{\mathrm{R}}_3\mathrm{CX}$ is most reactive towards S_N2 reaction?

Q. How will this justify the following order of acidic strength:
CH3CH2CHOOH>(CH3)2CHCOOH>(CH3)3COOH

Q.

"The acidic nature of alcohols is due to the polar nature of OH bond. And electron releasing group (-CH3, -C2H5) increases electron density on oxygen tending to decrease the polarity of O-H bond."

Please explain how increase in electron density on Oxygen atom decreases polarity.

Q. Which group is meta directing group ?

1. $-CC{l}_3$
2. $-OH$
3. $-N{H}_2$
4. $-C{H}_3$

Q. Which of the following is ortho/para directing and deactivating group?

1. $-Cl$
2. $-F$
3. $-Br$
4. All of the above

Q. The strongest ortho- para and strongest meta-directing groups respectively are

1. $-N{H}_{2}and-N{O}_2$
2. $-N{H}_{2}and-CON{H}_2$
3. $-N{O}_{2}and-N{H}_2$
4. $-Cland-CON{H}_2$

Q.

Which one of the following compounds is most acidic? a- ClCH2CH2OH. b- phenol. c- Ortho nitro phenol. d- Ortho cerosol. Please explain it to me

Q. Which of the following is ortho/para directing and deactivating group?

1. $-F$
2. $-Cl$
3. $-Br$
4. All of the above

Q.

Give a reason why ${\mathrm{H}}_2\mathrm{S}$ is less acidic than ${\mathrm{H}}_2\mathrm{Te}$.

Q. Which is more acidic CH3COOH or Br3COOH

Q. Nitrobenzene reacts with $B{r}_2$ in the presence of $FeB{r}_3$ to give m-bromonitrobenzene as the major product. Which of the following provides the best reason for the formation of m-bromonitrobenzene as the major product?

1. The electron density at the meta position is lesser than those at the ortho and para positions
2. Aromaticity is lost in the $\sigma$- complexes formed by the attack of $B{r}^{+}$ at the ortho and para positions but not at the meta position
3. The $\sigma -$ complex formed by the attachment of $B{r}^{+}$ at the meta position is the least destabilized and the most stable among the three $\sigma -$ complexes
4. In the final step of regeneration of benzene ring but the loss of $H^{+}$ from the $\sigma -$ complexes, the meta oriented $\sigma -$ complex loses $H^{+}$ most readily.

Q. Phenols do not react with:

1. Sodium bicarbonate
2. Sodium hydroxide
3. Potassium hydroxide
4. Ferric chloride

Q. Decreasing order of acidic strength of different (-OH) groups is

1. $a>b>d>c$
2. $a>c>b>d$
3. $c>a>b>d$
4. $c>b>a>d$

Q. Why does electron withdrawing group increases the acidity and releasing groups decrease the acidity of phenol?(proper and lucid explanation needed)

Q. Why phenoxide ion is more reactive than phenol towards electrophillic aromatic reaction

Q. Och3 group in withdrawing or donating to benzene ring

Q.

Which is more acidic Formic acid or Phenol?

Q. One mole of an unsaturated hydrocarbon on ozonolysis gives one mole each of $C{H}_{3}CHO,HCHO$ and $OHC-CHO$. The hydrocarbon is:

1. $C{H}_3-C{H}_2-CH=CH-C{H}_3$
2. $C{H}_2=CH-C{H}_2-CH=C{H}_2$
3. $C{H}_3-CH=CH-CH=C{H}_2$
4. $H_{2}C=CH-C{H}_2-C{H}_2-CHO$

Q. Match the compounds given in List-I with List-II and select the suitable option using the code given below :

List -I	List-II
(A) Benzaldehyde	(i) Phenolphthalein
(B) Phthalic anhydride	(ii) Benzoin condensation
(C) Phenyl benzoate	(iii) Oil of wintergreen
(D) Methyl salicylate	(iv) Fries rearrangement

Code :
(A) (B) (C) (D)

1. (iv) (i) (iii) (ii)
2. (ii) (iii) (iv) (i)
3. (ii) (i) (iv) (iii)
4. (iv) (ii) (iii) (i)

Q. Which of the following elements in an organic compound can be detected using ammonium molybdate?

1. Carbon
2. Nitrogen
3. Phosphorus
4. Sulphur

Q. Which one of the following will undergo meta substitution on monochlorination

1. Chlorobenzene

2. Phenol

3. Ethyl benzoate
4. Ethoxy ethane

Q. Nitrobenzene reacts with $B{r}_2$ in the presence of $FeB{r}_3$ to give m-bromonitrobenzene as the major product. Which of the following provides the best reason for the formation of m-bromonitrobenzene as the major product?

1. The electron density at the meta position is lesser than those at the ortho and para positions
2. Aromaticity is lost in the $\sigma$- complexes formed by the attack of $B{r}^{+}$ at the ortho and para positions but not at the meta position
3. The $\sigma -$ complex formed by the attachment of $B{r}^{+}$ at the meta position is the least destabilized and the most stable among the three $\sigma -$ complexes
4. In the final step of regeneration of benzene ring but the loss of $H^{+}$ from the $\sigma -$ complexes, the meta oriented $\sigma -$ complex loses $H^{+}$ most readily.

Q. STATEMENT-1: Phenols are less acidic than carboxylic acids.
STATEMENT-2: Weaker the conjugate base, stronger is the acid.

1. Both statements are true and STATEMENT-2 is the correct explanation of STATEMENT-1.
2. Both statements are true and STATEMENT-2 is not the correct explanation of STATEMENT-1
3. STATEMENT-1 is true but STATEMENT-2 is false
4. STATEMENT-1 is false but STATEMENT-2 is true

Q. what is the mechanism of the following reaction: benzoylation of benzene to produce benzophenon

Q. Which one of the following compounds would be easily oxidised by K2Cr207 in dil. H2SO4 1)CH3OH 2)(CH3)3COH 3)CH3CH2OH 4CH3CHO

Q. Identify incorrect statements.
I. Halo group activates benzene ring by mesomeric effect and destabilizes it by inductive effect.
II. Halo group is deactivating group.
III. Benzene is 10${}^4$ times more reactive than nitrobenzene towards nucleophile.
IV. $C{F}_3$ is a strongly deactivating group.

1. III only
2. II only
3. I, II, III
4. II, IV

Q. Is PH_{​​​​​3} a +m group or -m group?
Also give the stability order of +m group and -m group

Q. In benzene 1, 3 position is called

1. Odd position
2. Meta
3. Ortho
4. Para

Q. Four compounds A, B, C and D were heated individually with Tollen’s reagent. It was found that all compounds other than D formed a silver mirror on the inside of their test tubes. Identify the compound D.

1. Acetaldehyde
2. Butyraldehye
3. Acetone
4. Benzaldehyde