Nucleophilic Substitution in Alkyl Halides

Q. 1 litre of a hydrocarbon weights as much as one litre of CO2 at same P and T. Then what is the molecular formula of the hydrocarbon

Q. Order of reactivity towards nucleophilic substitution reaction of the compounds

1. $i>ii>iii>iv$
2. $ii>i>iii>iv$
3. $iv>iii>ii>i$
4. $iii>iv>ii>i$

Q. an aqueous solution containing 0.10g KIO3 (formula weight=214)was treated with excess of KI solution.the solution was acidified with HCl .the liberated I2 consumed 45.0mL of thiosulphate solution to decolourise the blue starch iodine complex.calculate the molarity of the sodium thiosulphate solution.

Q. 6. Which will undergo cationic hydrolysis? 1) NaCl 2) CH3COONa 3) (NH4)2SO4 4) H2CO3

Q. Which among the following compounds will undergo $S_{N}2$ reaction at the fastest rate ?

1. $({\mathrm{CH}}_3{)}_3\mathrm{CCl}$
   
2. $({\mathrm{CH}}_3{)}_2\mathrm{CHCl}$
   
3. ${\mathrm{CH}}_3\mathrm{Cl}$
   
4. ${\left(C_2{H}_5\right)}_2\mathrm{CHCl}$
   

Q.

Which will undergo SN2 reaction fastest among the following?

1. Ethyl fluoride

2. Ethyl chloride

3. Ethyl bromide

4. Ethyl iodide

Q. o-xylene on ozonolysis gives how many produc

Q.

Among the choices of alkyl bromide, the least reactive bromide in an SN2 reaction is:

1. 2-bromo-2-methylbutane

2. 1-bromopentane

3. 1-bromo-2-methylbutane

4. 1-bromo-3-methylbutane

Q. 26.1g of MnO2 react with 54.7 g of HCl ; MnO2 + 6HCl -> MnCl2 + 2H2O +Cl2 1. What is the volume 0of Co2 evolved 2. Which is limiting reagent. How much excess reagent required

Q. Which of the following compounds would not give ppt. with $AgN{O}_3$

1. $C{H}_{3}CH=CHCl$
2. $C{H}_2=CH-C{H}_{2}Cl$
3. 
4. $(C{H}_3{)}_{3}CCl$

Q.

The order of reactivity of the following alkyl halides for an SN² reaction is

1. RF > RCl > RBr >RI

2. RCl > RBr > RF > RI

3. RF > RBr > RCl > RI

4. RI > RBr > RCl > RF

Q.

Ethylidene chloride on hydrolysis with ag.KOH gives

1. CH₃CHO

2. CH₃COOH

3. CHCL₃

4. CH₃CH₂OH

Q. The correct order of rate of ${S_N}^2$ reactivity of $H_{2}O$, ${}^{-}OC{H}_3,{}^{-}OH$ and $C{H}_{3}CO{O}^{-}$ is

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

Q. pent2yne on ozonolysis followed by hydrolysis will give

Q. Which of these alkyl halides will undergo $S_{N}1$ reaction at the fastest rate?

1. $Cl-C{H}_2-CN$
2. $Cl-C{H}_2-N{O}_2$
3. $Cl-C{H}_2-OMe$
4. $Cl-C{H}_2-C{H}_3$

Q. 58 Is conjugation possible in the structure CH2=CH-O-H

Q. Which of the following will give the fastest nucleophilic substitution reaction by $S_{N}2$ pathway ?

1. 
2. 
3. 
4. 

Q.

tert-alkyl halides are practically inert to substitution by SN2 mechanism because of:

1. Insolubility

2. Instability

3. Inductive effect

4. Steric hindrance

Q.

Explain the important aspects of resonance with reference to the ion.

Q. 25.2.5ml of 2/5M weak monoacidic base (kb=10 to the power -12 at 25 degree Celsius) is titrated with 2/15M Hcl in water at 25 degree Celsius. Find the concentration of H plus ions at equivalence point. (kw=10 to the power -14 at 25 degree Celsius)

Q. $C{H}_{3}Br\stackrel{KCN}{\to }A\stackrel{H_3{O}^{+}}{\to }B$

$B$ is :

1. $C{H}_{3}N{H}_2$
2. $(C{H}_3{)}_{2}NH$
3. $C_2{H}_{5}N{H}_2$
4. $C{H}_{3}COOH$

Q. Which of the following pair of compound will have the same order of rate of $S_{N}1$ and $S_{N}2$ ?

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

Q. Why riversible reaction doesnt complete?

Q.

$S_{N}1$ solvolysis of 1-(bromomethyl)cyclohex-1-ene in ethanol gives:

1. The reaction produces a single major product

2. The reaction produces several products in nearly equal proportions

3. The reaction proceeds via a resonance-stabilized carbocation

4. The reaction is $S_{N}2$

Q.

To synthesize the given compound via an $S_{N}2$ reaction, themost appropriate combination is:

1. 

2. 

3. 

4. None of the above

Q. Which of the following is correct order of decreasing $S_{N}2$ reactivity?

1. $R_{2}CHX>R_{3}CX>RC{H}_{2}X$
2. $RC{H}_{2}X>R_{3}CX>R_{2}CHX$
3. $RC{H}_{2}X>R_{2}CHX>R_{3}CX$
4. $R_{3}CX>R_{2}CHX>RC{H}_{2}X$ (X = halogen)

Q.

Addition of KI accelerates the hydrolysis of primary haloalkanes because

1. KI is soluble in organic solvent

2. I^- is a strong base

3. I^-is a weak base and a poor leaving group

4. I^- is a powerful nucleophile as well as a good leaving group

Q.
$\begin{array}{cc}\text{List -I}& \text{List -II}\\ \text{(I) Enantiomeric Pairs}& \left(P\right)20\\ \text{(II) Diastereomeric Pairs}& \left(Q\right)34\\ \text{(III) Optically acitve compounds}& \left(R\right)18\\ \text{(IV) Number of fractions of compounds that can be separated}& \left(S\right)11\\ \text{by fractional distillation}& \\ & \left(T\right)9\\ & \left(U\right)32\end{array}$
Which of the following options has the correct combination considering List-I and List-II

1. (I), (T) and (II), (Q)
2. (II), (U) and (IV), (S)
3. (III), (R) and (IV), (T)
4. (II), (U) and (III), (T)

Q.

It is given that when (±)-2, 3-dibromobutane reacts with $KOH$, some of the products formed are:

1. (2S, 3R)-3-bromo-butan-2-ol
2. (2R, 3S)-3-bromo-butan-2-ol

Explain via mechanism and then choose the correct ones from the following.

1. Monosubstitution of (2S, 3S)-2, 3-dibromobutane using $O{H}^{-}$ yields a mixture of products.

2. Monosubstitution of (2R, 3R)-2, 3-dibromobutane using $O{H}^{-}$ yields a mixture of products.

3. Monosubstitution of (2S, 3S)-2, 3-dibromobutane using $O{H}^{-}$ yields a single major product.

4. Monosubstitution of (2S, 3S)-2, 3-dibromobutane using $O{H}^{-}$ yields a mixture of products.

Q.

Predict all the possible products for the reaction of 2-chlorobutane with alcoholic $KOH$.

1. 1-Butene
2. Cis-2-butene
3. Trans-2-butene
4. 2-Butyne