Which of the following reactions is an example of a nucleophilic substitution reaction?

1. RX + KOH → ROH + KX

2. 2RX + 2Na →R — R + 2NaX

3. RX + H₂→RH + HX

4. RX + Mg →RMg X

Which one is most reactive towards S_N1 reaction?

1. $C_6{H}_{5}CH\left(C_6{H}_5\right)Br$

2. $C_6{H}_{5}CH\left(C{H}_3\right)Br$

3. $C_6{H}_{5}C\left(C{H}_3\right)\left(C_6{H}_5\right)Br$

4. $C_6{H}_{5}C{H}_{2}Br$

Among cyclohexanol (I), acetic acid (II), 2, 4, 6-trinitrophenol (III) and phenol (IV) the correct order of decreasing acidic character will be:

Among the following compounds the one that is most reactive towards electrophilic nitration is:
1. Benzoic acid
2. Nitrobenzene
3. Toluene
4. Benzene

Some meta-directing substituents in aromatic substitution are given.
Most deactivating group among the following is: 

1. –SO₃H

2. –COOH

3. –NO₂

4. –C≡N

Which of the following is the most correct electron displacement for a nucleophilic reaction to take place? 

1.
2.
3.
4.

Following is the list of some aromatic compounds. Select the correct sequence of decreasing order of reactivity for electrophilic aromatic substitution reaction using the answer codes given below:

a. ${\mathrm{C}}_6{\mathrm{H}}_5 - \mathrm{OH}$

b. ${\mathrm{C}}_6{\mathrm{H}}_5 - {\mathrm{CH}}_3$

c. ${\mathrm{C}}_6{\mathrm{H}}_5 - {\mathrm{NO}}_2$

d. ${\mathrm{C}}_6{\mathrm{H}}_5 - \mathrm{CHO}$

Answer codes :

1. a d b c

2. c d b a 

3. a b d c

4. a b c d

Arrange the decreasing order of reactivity of these compounds for nucleophilic substitution reaction.

a. ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{O}-\underset{\underset{\mathrm{O}}{\left|\right|}}{\overset{\stackrel{\mathrm{O}}{\left|\right|}}{\mathrm{S}}}-{\mathrm{CF}}_3$

b. ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{O}-\mathrm{TsCl}$

c. ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{Cl}$

d. ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{Br}$

Select the correct answer from the codes given below:

Codes:

1. c, d, a, b

2. c, d, b, a

3. a, b, c, d

4. a, b, d, c

Arrange decreasing order of reactivity of given compounds with NBS/ ${\mathrm{CCl}}_4$/ hv:

a. ${\mathrm{C}}_6{\mathrm{H}}_5-{\mathrm{CH}}_3$

b. ${\mathrm{C}}_6{\mathrm{H}}_5-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_3$

c. ${\mathrm{C}}_6{\mathrm{H}}_5-{\mathrm{CH}}_2-\mathrm{CH}={\mathrm{CH}}_2$

d. ${\mathrm{C}}_6{\mathrm{H}}_5-\underset{\underset{{\mathrm{CH}}_3}{|}}{\mathrm{C}}\mathrm{H}-\mathrm{CH}={\mathrm{CH}}_2$

Select the correct answer from the codes given below:

Codes :

1. d c a b

2. d c b a 

3. a b c d

4. a c b d