Energy Diagrams of SN1 and SN2

Q. In the given reaction rate is fastest, when (X) is:

1. -OH
2. $-N{H}_2$
3. 
4. 

Q. Consider the following carbocations
I. $C{H}_3-C^{⨁}{H}_2$
II. $C{H}_2=C^{⨁}H$
III. $C{H}_2=CH-C^{⨁}{H}_2$
IV. $C_6{H}_5-C{H}_2^{⨁}$
Stability of these carbocations in decreasing order is?

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

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

Q. Which of the following statements are correct about the reactivities of $\left(I\right)$ $n$-propyl chloride and $\left(II\right)$ allyl chloride?

1. Rate if $S_{N}1$ reaction of $\left(I\right)>\left(II\right)$
2. Rate if $S_{N}1$ reaction of $\left(II\right)>\left(I\right)$
3. Rate if $S_{N}2$ reaction of $\left(I\right)>\left(II\right)$
4. Rate if $S_{N}2$ reaction of $\left(II\right)>\left(I\right)$

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

Match the potential energy curve with carbocation.

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

Q. Show how is carbanion : ${\overline{CH}}_2-\stackrel{\stackrel{O}{\parallel }}{C}-C{H}_3$ Stabilised by resonance?