Reactions of Alkyl Halides

Q. KI in acetone, undergoes $S_{N}2$ reaction with each P, Q, R and S. The rates of the reaction vary as

1. P > Q > R > S
2. S > P > R > Q
3. P > R > Q > S
4. R > P > S > Q

Q. Which of the following compound will undergo $S_{N}1$ reaction?

1. 
2. 
3. 
4. All the above

Q.

What happes when

n - butyl chloride is treated with alcoholic KOH.

bromobenzene is treated with Mg in the presence of dry ether.

Chlorobenzene is subjected to hydrolysis.

Ethyl chloride is treated with aqueous KOH

methyl bromide is treated with sodium in the presence of dry ether.

methyl chloride is treated with KCN ?

Q. For the following carbocations the correct order of stability is
I : ${}^{\oplus }C{H}_2-COC{H}_3$ II : ${}^{\oplus }C{H}_2-OC{H}_3$ III : ${}^{\oplus }C{H}_2-C{H}_3$

1. I < II < III
2. II < I < III
3. III < II < I
4. I < III < II

Q. Reaction of $C_6{H}_{5}C{H}_{2}Br$ with aqueous sodium hydroxide follows_____

1. $S_{N}1$ mechanism
2. $S_{N}2$ mechanism
3. Any of the above two depending upon the temperature of reaction
4. Saytzeff's rule

Q. Write the main products when
(i) n-butyl chloride is treated with alcoholic KOH.
(ii) 2, 4, 6-trinitrochlorobenzene is subjected to hydrolysis.
(iii) methylchloride is treated with AgCN.

Q. An organic compound $A\left(C_6{H}_{6}O\right)$ gives dark green colouration with ferric chloride. On treatment with $CHC{l}_{3}andKOH$, followed by acidification gives compound $B$. Compound $B$ can also be obtained from compound $C$ on reaction with pyridinium chlorochromate $\left(PCC\right)$. Identify $A,BandC$

1. 
2. 
3. 
4. 

Q. In which of the following reaction, the major product alkene is formed by $E_{1}cB$ mechanism?

1. 
2. 
3. 
4. 

Q.

Which of the following is an appropriate set of reactants for the preparation of 1-methoxy-4-nitrobenzene and why?

(i)

(ii)

Q. Rank the following species in order of decreasing nucleophilicity in a polar protic solvent:

1. $3>1>2$
2. $2>3>1$
3. $1>3>2$
4. $2>1>3$

Q. The species $C{H}_3\stackrel{+}{C}HC{H}_3$ is less stable than:

1. $(C{H}_3{)}_3\stackrel{+}{C}$
2. $C{H}_{3}C{H}_2\stackrel{+}{C}{H}_2$
3. $C{H}_3\stackrel{+}{C}{H}_2$
4. $\stackrel{+}{C}{H}_3$

Q. When silver propanoate is treated with $I_2$ in $CC{l}_4$, the major product formed is

1. n-propyl propanoate
2. ethyl propanoate
3. 1-iodoethane
4. iodoethane

Q. Which of the following will give $S_{N}1$ reaction quickly?

1. 
2. 
3. 
4. All of the above at equal rate

Q. What is the type of amine obtained from the ammonolysis of alkyl halides?

1. Primary
2. Primary and secondary
3. Secondary and tertiary
4. Primary, secondary and tertiary

Q. The correct increasing order of the rate of reaction for alkyl halides undergoing $E_1$ and $E_2$ reaction respectively is:
Here,
$1^{\circ }\text{is primary alkyl halide}$
$2^{\circ }\text{is secondary alkyl halide}$
$3^{\circ }\text{is tertiary alkyl halide}$

1. $E_1:1^{\circ }<2^{\circ }<3^{\circ }{E}_2:1^{\circ }<2^{\circ }<3^{\circ }$
2. $E_1:1^{\circ }<2^{\circ }<3^{\circ }{E}_2:3^{\circ }<2^{\circ }<1^{\circ }$
3. $E_1:3^{\circ }<2^{\circ }<1^{\circ }{E}_2:1^{\circ }<2^{\circ }<3^{\circ }$
4. $E_1:3^{\circ }<2^{\circ }<1^{\circ }{E}_2:3^{\circ }<2^{\circ }<1^{\circ }$

Q. The order of decreasing nucleophilicity is

1. $H_{2}O>O{H}^{-}>C{H}_{3}CO{O}^{-}>C{H}_3{O}^{-}$
2. $C{H}_{3}CO{O}^{-}>C{H}_3{O}^{-}>H{O}^{-}>H_{2}O$
3. $H{O}^{-}>C{H}_3{O}^{-}>C{H}_{3}CO{O}^{-}>H_{2}O$
4. $C{H}_3{O}^{-}>O{H}^{-}>C{H}_{3}CO{O}^{-}>H_{2}O$

Q. An optically active compound A upon acid catalysed hydrolysis yields two optically active compounds B and C by pseudo first order kinetics with respect to A. The observed rotation of the mixture after 20 min was 5° while after completion of the reaction it was – 20°. If the optical rotation per molar concentration of A, B and C are 60°, 40° and – 80° respectively and the observed rotation of a compound is directly proportional to the concentration of that compound. (Take optical rotation in degree)

$\begin{array}{cc}\text{List -I}& \text{List -II}\\ \text{(I) Rate constant of the reaction (in}hou{r}^{-1})& \left(P\right)1.0\\ \text{(II) Initial concentration of compound A (in M)}& \left(Q\right)2.08\\ \text{(III) If the initial concentratrion of A is 0.8 M then}& \left(R\right)0.5\\ \text{the observed optical rotation of mixture after 1 hour}& \\ \text{(IV) If initially along with A;B and C are also present with}& \left(S\right)-22\\ \text{initial concentration [A] = 0.4M, [B] = 0.1 M and [C] = 0.2 M}& \\ \text{then net observed optical rotation of the mixture after 40 min.}& \left(T\right)22\\ & \left(U\right)-18\end{array}$

Which of the following options has the correct combination considering List-I and List-II

1. (I), (Q)
2. (II), (P)
3. (II), (R)
4. (I), (P)

Q. What is the difference between 1.Allyl Halides and Allylic Halides 2.Benzyl Halides and Benzylic Halides And which of the two in both the cases shows Sn1 and Sn2?

Q. During the course of an $S_{N}1$ reaction, the intermediate species formed is:

1. a carbocation
2. a free radical
3. a carbanion
4. an intermediate complex

Q. From each of the following pairs select the compound that will react faster with sodium iodide in acetone
(a) 2-Chloropropane or 2-bromopropane
I II
(b) 1-Bromobutane or 2-bromobutane
I II

1. (a) - I, (b) - I
2. (a) - I, (b) - I
3. (a) - I, (b) - I
4. (a) - II, (b) - I

Q. Benzyl chloride on oxidation with copper nitrate gives

1. Benzoic acid
2. benzyl alcohol
3. Benzyl acetate
4. Benzaldehyde

Q. Which one of the following has maximum nucleophilicity?

1. $C{H}_3{S}^{\ominus }$
2. $C_6{H}_5-\stackrel{\ominus }{O}$
3. $E{t}_{3}N$
4. $F^{\ominus }$

Q.

what does trans elimination reaction mean?

Q. Sec-butyl alcohol on heating with conc. $H_{2}S{O}_4$ at 443K gives

1. sec-butyl hydrogen sulphate
2. Ethoxy Ethane
3. but-2-ene
4. but-1-ene

Q. dx/dt =k[A]^0.5[B]^0.5[C]^0.5, what will be the order of the reaction?

Q. Pick out most reactive alkyl halide for $S_{N}1$ reaction.

1. 
2. 
3. 
4. 

Q. The reagent used for converting ethanoic acid to ethanol is

1. $LiAl{H}_4$
2. $KMn{O}_4$
3. $PC{l}_3$
4. $K_{2}C{r}_2{O}_7/H^{+}$

Q. Which of the following potential energy (PE) diagram represents the $S_{N}1$ reaction?

1. 
2. 
3. 
4. 

Q. Identify the structure of [B] in following sequence of reactions.

1. 
2. 
3. 
4. 

Q. Consider the given reaction

Which of the following statement(s) is/are correct for above reaction?

1. It is a concerted reaction
2. The reaction follows $S_{N}2$ mechanism
3. The reaction follows $S_{N}1$ mechanism
4. Configuration of product is (R)