Stereochemistry of the Products in SN1 and SN2 Reactions

Q. Which of the following statement(s) is/are true for the following reaction?

(1) It involves a carbocation intermediate
(2) Rearrangement is due to $S_{N}1$ mechanism.
(3) It proceeds via $S_{N}2$ pathway.
(4) It involves neighbouring group participation.

1. (1), (2)
2. (2), (4)
3. (1), (2), (4)
4. (3), (4)

Q. A reaction gives the following result:

What would be the percentage of back side attack of the reagent assuming the reaction is completed?

1. 35%
2. 65%
3. 85%
4. 30%

Q.
In the following graph, stability of above carbocations have been shown:

Match the potential energy curve with carbocation.

1. $\begin{array}{cccc}& \text{I}& \text{II}& \text{III}\\ \text{(b)}& \text{B}& \text{A}& \text{C}\end{array}$
2. $\begin{array}{cccc}& \text{I}& \text{II}& \text{III}\\ \text{(c)}& \text{C}& \text{B}& \text{A}\end{array}$
3. $\begin{array}{cccc}& \text{I}& \text{II}& \text{III}\\ \text{(a)}& \text{A}& \text{B}& \text{C}\end{array}$
4. $\begin{array}{cccc}& \text{I}& \text{II}& \text{III}\\ \text{(d)}& \text{C}& \text{A}& \text{B}\end{array}$

Q. 2-chlorobutane obtained by chlorination of butane, will be:

1. Meso-form
2. l - form
3. d - form
4. Racemic form

Q. Reaction of R-2-bromobutane with aqueous KOH follows two parallel reactions, one by $S_{N}2$ (complete inversion) and other by $S_{N}1$ (complete racemization). Specific optical activity for R-2-butanol is $-{13.50}^{\circ }/gmL$ per dm length of the polarimeter.


If in a 10 cm tube polarimeter, 10 ml of R-2-bromobutane along with KOH is filled, then after complete reaction of R-2-bromobutane, the mass of all alcohols formed is found equal to 5 g of which 1 g is of R-2-butanol. Then, the total optical rotation (in degree) of the solution is

Q.
In the following graph, stability of above carbocations have been shown:

Match the potential energy curve with carbocation.

1. $\begin{array}{cccc}& \text{I}& \text{II}& \text{III}\\ \text{(a)}& \text{A}& \text{B}& \text{C}\end{array}$
2. $\begin{array}{cccc}& \text{I}& \text{II}& \text{III}\\ \text{(d)}& \text{C}& \text{A}& \text{B}\end{array}$
3. $\begin{array}{cccc}& \text{I}& \text{II}& \text{III}\\ \text{(c)}& \text{C}& \text{B}& \text{A}\end{array}$
4. $\begin{array}{cccc}& \text{I}& \text{II}& \text{III}\\ \text{(b)}& \text{B}& \text{A}& \text{C}\end{array}$

Q. A reaction gives the following result:

What would be the percentage of back side attack of the reagent assuming the reaction is completed?

1. 35%
2. 85%
3. 65%
4. 30%

Q. A reaction gives the following result:

What would be the percentage of back side attack of the reagent assuming the reaction is completed?

Q. Reaction of R-2-bromobutane with aqueous KOH follows two parallel reactions, one by $S_{N}2$ (complete inversion) and other by $S_{N}1$ (complete racemization). Specific optical activity for R-2-butanol is $-{13.50}^{\circ }/gmL$ per dm length of the polarimeter.


If in a 10 cm tube polarimeter, 10 ml of R-2-bromobutane along with KOH is filled, then after complete reaction of R-2-bromobutane, the mass of all alcohols formed is found equal to 5 g of which 1 g is of R-2-butanol. Then, the total optical rotation (in degree) of the solution is

Q. Given are the structures of cyclic D-glucoside.

1. $2,2$
2. $3,3$
3. $2,3$
4. $3,2$