Bromination of Alkene

Q. Which one is a nucleophilic substitution reaction among the following?

1. 
2. $C{H}_{3}CHO+HCN\to C{H}_{3}CH\left(OH\right)CN$
3. 
4. 

Q.

In a ${\mathrm{S}}_{\mathrm{N}}1$ reaction of alkyl halide on chiral centres, there is _______.

Q.

Assertion : Addition of bromine to trans-2-butene yields meso-2, 3-dibromobutane

Reason : Bromine addition to an alkene is an electrophilic addition.

1. If both assertion and reason are true and the reason is the correct explanation of the assertion.

2. If both assertion and reason are true but reason is not the correct explanation of the assertion.
3. If assertion is true but reason is false.
4. If the assertion and reason both are false.

5. If assertion is false but reason is true.

Q.

What is the main product of the reaction between 2-methyl propene with hydrogen bromide?

[RPMT 2002]

1. 2-bromo-2 methyl propane

2. 1-bromo butane

3. 1-bromo-2 methyl propane

4. 2-bromo butane

Q. Arrange the following alkyl halides in increasing order of the rate of $\beta$-elimination reaction with alcoholic $KOH$.

1. $\left(ii\right)>\left(iii\right)>\left(i\right)$
2. $\left(iii\right)>\left(ii\right)>\left(i\right)$
3. $\left(i\right)>\left(ii\right)>\left(iii\right)$
4. $\left(ii\right)>\left(i\right)>\left(iii\right)$

Q. Elimination reaction of 2-bromobutane to form but-2-ene is:
(a) $\beta$-Elimination reaction
(b) Follows Hoffmann rule
(c) Dehydrohalogenation reaction
(d) Dehydration reaction

1. (a), (c) and (d) only
2. (b) and (c) only
3. (a), (b) and (d) only
4. (a) and (c) only

Q. In methyl alcohol solution, bromine reacts with ethylene to yield $BrC{H}_{2}C{H}_{2}OC{H}_3$ in addition to 1, 2-dibromoethane because

1. The methyl alcohol solvates the bromine
2. The ion formed initially may react with $B{r}^{-}$ or $C{H}_{3}OH$
3. The reaction follows Markownikoff's rule
4. This is a free-radical mechanism

Q. Which one of the following is incorrect statement regarding $S_{N}2$ reaction?

1. Polar aprotic solvent favour $S_{N}2$ reaction
2. Strong nucleophiles are preferred
   
3. Nucleophile is involved in the RDS
4. Rate depends on R-X only

Q. Which of the following is/are conditions for $S_{N}NGP$ reaction to occur?

1. Nucleophile should be present within the molecule/internally.
2. Generally, nucleophile and leaving group should be present anti to each other at 1, 2 position.
   
3. Nucleophile and leaving group should be present syn to each other
4. Concentration of nucleophile (external) should be less

Q. In which case , the product is neither a cyclic ether nor open chain symmetrical ether

1. 
   $C{H}_3-CH=CH-C{H}_3\stackrel{C_6{H}_{5}C{O}_{3}H}{\to }$
2. $C{H}_{3}C{H}_{2}ONa+C_2{H}_{5}Br\to$
3. $KCN+(C{H}_3{)}_{3}CBr\to$
4. $C_2{H}_{5}OH\left(Excess\right)+H_{2}S{O}_4\stackrel{{140}^{\circ }\text{C}}{\to }$

Q. Which one of the following is correct regarding $S_{N}1$ reaction?

1. Polar aprotic solvent favour $S_{N}1$ reaction?
2. Strong nucleophiles are preferred
   
3. Nucleophile is involved in the RDS.
   
4. Rate depends on R-X

Q.

Which of the following reactions will result in the formation of a chiral center in the product?

1. ${\mathrm{CH}}_3\mathrm{CH}={\mathrm{CH}}_2\mathrm{HBr}\to$

2. ${\mathrm{CH}}_2={\mathrm{CH}}_2+\mathrm{HOBr}\to$

3. ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{CH}={\mathrm{CH}}_2+\mathrm{HBr}\to$

4. ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{CH}={\mathrm{CH}}_2+\mathrm{HBr}\stackrel{{\mathrm{H}}_2{\mathrm{O}}_2}{\to }$

Q. 8 Assertion: P nitrochlorobenzene is more reactive then benzyl chloride for SN1 mechanism reason: it is a nucleophilic substitution reaction

Q. What are meso compound?

Q. For the given two reactions, choose the correct option:

1. Reaction $I$ gives a substitution product whereas reaction $II$ gives an elimination product.
2. Reaction $I$ gives an elimination product whereas reaction $II$ gives a substitution product.
3. Both reactions give elimination products.
4. Both reactions give substitution products.

Q. Identify (X), (Y) and (Z) reagents in the given sequence of reaction. $CH\equiv CH\stackrel{X}{\to }C{H}_{3}CHO\stackrel{Y}{\to }C{H}_{3}CH\left(OH\right)C{H}_3\stackrel{Z}{\to }C{H}_{3}COC{H}_3$

1. $X=H_{2}S{O}_4$, $Y=H_3{O}^{+}$, $Z=PC{l}_5,\text{heat}$
2. $X=HN{O}_3$, $Y=N{a}_{2}C{O}_3$, $Z=H_{2}S{O}_4$
3. $X=H_{2}S{O}_4/H{g}^{2+}$, $Y=PC{l}_5/H_{2}O$, $Z=K_{2}C{r}_2{O}_7/O{H}^{-}$
4. $X=H_{2}S{O}_4/H{g}^{2+},$ $Y=C{H}_{3}MgBr/H_{2}O,$ $Z=K_{2}C{r}_2{O}_7/H^{+}$

Q. Compound C (major product) will be:

1. 
2. 
3. 
4. 

Q.
The major product of this reaction is:

1. 
2. 
3. 
4. 

Q. Which statement(s) is/are correct?
I) Benzene decolourises bromine water.
II) Benzene decolourises alkaline permanganate solution.
III) Acetylene decolourises alkaline permanganate solution.
IV) Acetylene decolourises bromine water.

1. III and IV
2. II and III
3. I and IV
4. I and II

Q. Identify 'A' in the following chemical reaction.

1. 
2. 
3. 
4. 

Q. Which of the following compound is resistant to nucleophilic attack of $O{H}^{-}$ ion?

1. acetamide
2. acetonitrile
3. methyl acetate
4. diethyl ether

Q. Identify the products X and Y formed in the following reaction:

1. $X=C{H}_{3}C{H}_{2}C{H}_{2}C{H}_{2}C{H}_{2}Cl,Y=C{H}_{3}C{H}_2-\underset{Cl}{\underset{|}{C}}H-C{H}_{2}C{H}_3$
2. $X=C{H}_{3}C{H}_2-\underset{Cl}{\underset{|}{C}}H-C{H}_{2}C{H}_3,Y=C{H}_{3}C{H}_{2}C{H}_2-\underset{Cl}{\underset{|}{C}}H-C{H}_3$
3. $X=C{H}_{3}C{H}_2-\underset{Cl}{\underset{|}{C}}H-C{H}_{2}C{H}_3,Y=C{H}_3-\underset{Cl}{\underset{|}{C}}H-\underset{Cl}{\underset{|}{C}}H=C{H}_{2}C{H}_3$
4. $X=ClC{H}_2-C{H}_2-CH=CH-C{H}_3,Y=C{H}_{3}C{H}_2-CH=CH-C{H}_{2}Cl$

Q.

What is the main product of the reaction between 2-methyl propene with hydrogen bromide?

[RPMT 2002]

1. 1-bromo butane

2. 1-bromo-2 methyl propane

3. 2-bromo butane

4. 2-bromo-2 methyl propane

Q.

$H_{3}C-C{H}_2-\underset{\stackrel{|}{C{H}_3}}{C}=C{H}_2+HBr\to A$
A (predominantly) is

1. 
2. 
3. 
4. 

Q. The stereoisomers that are formed by electrophilic addition of bromine to tans-but-$2$-ene is/are :

(JEE MAIN 2021)

1. $2$ identical mesomers
2. $2$ enantiomers and $2$ mesomers
3. $2$ enantiomers
4. $1$ racemic and $2$ enantiomers

Q. $2$-methyl butane on reaction with $B{r}_2$ in the presence of sunlight mainly gives:

1. $1$-Bromo-$3$-methylbutane
2. $2$-Bromo-$3$-methylbutane
3. $2$-Bromo-$2$-methylbutane
4. $1$-Bromo-$2$-methylbutane

Q. Reforming (also called aromatization) is the conversion of aromatic hydrocarbons into aliphatic hydrocarbons containing the same number of carbon atoms.

1. True
2. False

Q. When hydrochloric acid gas is treated with propene in presence of benzoyl peroxide, it gives:

1. 2-Chloropropane
2. Allyl chloride
3. No reaction
4. n-propyl chloride

Q. Arrangement of $(C{H}_3{)}_{3}C-,(C{H}_3{)}_{2}CH-,C{H}_3-C{H}_2-$ when attached to benzyl or an unsaturated group in increasing order of inductive effect is :

1. $(C{H}_3{)}_{3}C-<C{H}_3-C{H}_2-<(C{H}_3{)}_{2}CH-$
2. $C{H}_3-C{H}_2-<(C{H}_3{)}_{2}CH-<(C{H}_3{)}_{3}C-$
3. $(C{H}_3{)}_{3}C-<(C{H}_3{)}_{2}CH-<C{H}_3-C{H}_2$
4. $(C{H}_3{)}_{2}CH-<(C{H}_3{)}_{3}C-<C{H}_3-C{H}_2-$

Q. How will you obtain 1-bromopropane from propene ?