Hyperconjugation

Q.

The order of basicity among the following compounds is:

1. II > I > IV > III

2. I > IV > III > II

3. IV > II > III > I

4. IV > I > II > III

Q.

The formula of a gaseous hydrocarbon requires $6$times its own volume of ${\mathrm{O}}_2$for complete oxidation and produces 4 times its own volume of ${\mathrm{CO}}_2$ is ${\mathrm{C}}_{\mathrm{x}}{\mathrm{H}}_{\mathrm{y}}$. The value of $\mathrm{y}$ is

Q. Arrange the following alkenes in the order of their stability.

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

Q. Choose the correct statement regarding the given alkenes:

1. $I$ has more $\alpha$-hydrogens than $II$.
2. Stability of $I$ is more than stability of $II$.
3. Stability of $I$ is less than stability of $II$.
4. Both $I$ and $II$ are equally stable.

Q. Total number of $\alpha$-hydrogens in the given structure is :

1. 4
2. 5
3. 6
4. 7

Q.

What is the stability order of carbocation?

Q. Arrange the following in decreasing order of reactivity towards electrophilic aromatic substitution

1. $\left(a\right)>\left(b\right)>\left(c\right)$
2. $\left(c\right)>\left(b\right)>\left(a\right)$
3. $\left(a\right)>\left(c\right)>\left(b\right)$
4. $\left(c\right)>\left(a\right)>\left(b\right)$

Q. Which of the following is the most stable carbocation ?

1. 
2. 
3. 
4. 

Q. Among the given cations, the most stable carbonium ion is

1. sec-butyl
2. tert-butyl
3. n-butyl
4. None of these

Q. The number of hyperconjugative structures involving C-H bond resonance are :

Q. The order of heat of hydrogenation in following compound is:

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

Q. Hyperconjugation is not observed in:

1. A free radical $(-\stackrel{\bullet }{C}{H}_2)$
2. A carbanion $(-\stackrel{-}{C}{H}_2)$
3. A carbocation $(-\stackrel{+}{C}{H}_2)$
4. A double bond $\text{>C=C<}$

Q. The decreasing order of the stabilities of the following alkenes is:

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

Q.

The stability of $M{e}_{2}C=C{H}_2$ is more than that of $MeC{H}_{2}CH=C{H}_2$ due to:

1. Inductive effect of the Me group

2. resonance effect of the Me group

3. Hyperconjugative effect of the Me group.

4. resonance as well as inductive effect of the Me group.

Q. Larger the number of hyperconjugative structures, the stability of carbocation will

1. Increase
2. Decrease
3. Remains same
4. None of the mentioned

Q. Larger the number of hyperconjugative structures, the stability of carbocation will

1. Increase
2. Decrease
3. Remains same
4. None of the mentioned

Q. The correct order for the increasing heat of hydrogenation for the following structures is :

1. $\left(a\right)<\left(b\right)<\left(c\right)$
2. $\left(b\right)<\left(c\right)<\left(a\right)$
3. $\left(c\right)<\left(b\right)<\left(a\right)$
4. $\left(a\right)<\left(c\right)<\left(b\right)$

Q. Which of the following is the correct order for heat of hydrogenation of these compounds?

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

Q. Hyperconjugation occurs in which of the following?

1. 
2. 
3. 
4. 

Q. Hyperconjugation in ethene is not possible.

1. False
2. True

Q. Which of the following has the most negative heat of hydrogenation?

1. 
2. 
3. 
4. 

Q. Which of the following free radical is most stable?

1. $\begin{array}{c}C{H}_3-\stackrel{\stackrel{H}{|}}{\underset{\underset{C{H}_3}{|}}{C^{\cdot }}}\end{array}$
2. $\begin{array}{c}C{H}_3-\stackrel{\stackrel{C{H}_3}{|}}{\underset{\underset{C{H}_3}{|}}{C^{\cdot }}}\end{array}$
3. $\begin{array}{c}{}^{\cdot }C{H}_3\end{array}$
4. $\begin{array}{c}C{H}_3-\stackrel{\cdot }{C}{H}_2\end{array}$

Q. The stability order of $\pi$ - bond in following alkenes in the increasing order is:
$\underset{\left(I\right)}{C{H}_3-CH=C{H}_2}$

$\underset{\left(II\right)}{C{H}_3-\underset{\underset{C{H}_3}{|}}{C}=\underset{\underset{C{H}_3}{|}}{C}-C{H}_3}$

$\underset{\left(III\right)}{C{H}_3-\underset{\underset{C{H}_3}{|}}{C}=C{H}_2}$

$\underset{\left(IV\right)}{C{H}_3-\underset{\underset{C{H}_3}{|}}{C}=CH-C{H}_3}$

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

Q. Total number of $\alpha$-hydrogens in the given structure is :

1. 4
2. 5
3. 6
4. 7

Q. Which of the following molecule has highest electron density in the phenyl ring?

1. 
2. 
3. 
4. 

Q. Which one of the following is known as $\sigma -\pi$ resonance?

1. Resonance effect
2. Hyperconjugation
3. Inductive effect
4. Electromeric effect

Q. Arrange the following alkenes in order of their decreasing heat of combustion values:

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

Q. Assertion (A) : Alkene A $(M{e}_{2}C=CM{e}_2)$ is more stable than alkene $(E{t}_{2}C=CE{t}_2)$.
Reason (R) : Baker-Nathan effect.

1. If both (A) and (R) are true and (R) is the correct explanation of (A).
2. If both (A) and (R) are true and (R) is not the correct explanation of (A).
3. If (A) is true but (R) if false
4. If (A) is false but (R) if true

Q.

The stability of (CH₃)₂C=CH₂ is more than that of CH₃CH₂CH=CH₂ due to

1. inductive effect of the methyl group

2. resonance effect of methyl group

3. hyperconjugative effect of the methyl group

4. resonance and inductive effect of methyl group.

Q.

The total number of contributing structures showing hyperconjugation (involving $C-H$ bond) for the following carbocation is ___