Hyperconjugation

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. Which one is the correct order of acidity?

1. $CH\equiv CH>C{H}_2=C{H}_2>C{H}_3-C\equiv CH>C{H}_3-C{H}_3$
2. $C{H}_3-C{H}_3>C{H}_2=C{H}_2>C{H}_3-C\equiv CH>CH\equiv CH$
3. $C{H}_2=C{H}_2>C{H}_3-CH=C{H}_2>C{H}_3-C\equiv CH>CH\equiv CH$
4. $CH\equiv CH>C{H}_3-C\equiv CH>C{H}_2=C{H}_2>C{H}_3-C{H}_3$

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

Q.

Consider the following compounds

hyperconjugation occurs in

1. I only

2. II only

3. I and III

4. III only

Q. Which is the least stable carbocation?

1. $(C{H}_3{)}_{2}H{C}^{+}$
2. $H_3{C}^{+}$
3. $C{H}_{3}C{H}_2^{+}$
4. $(C{H}_3{)}_3{C}^{+}$

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

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

Q. Which is more stable N2- or N2+ and why, since the bond order will be the same?

Q.

Why hyperconjugation is called no bond resonance?

Q. Q)What would be the board level definition of synergic effect ?????
And how synergic effect strengthens the bond between metal and the carbonyl group ??????
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Q. Hyperconjugation is not observed in:

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

Q.

Which of The Following Molecule Is Planar?

1. ${\mathrm{CH}}_4$

2. ${\mathrm{C}}_2{\mathrm{H}}_4$

3. ${\mathrm{PCl}}_3$

4. ${\mathrm{SiCl}}_4$

Q. Choose the correct statement(s) regarding reverse hyperconjugation :

1. It is a destabilizing effect.
2. Takes place when $\alpha$-hydrogens are there in a conjugated system.
3. The electron density flows from $\sigma$-orbital to empty p-orbital.
4. $Ph-CC{l}_3$ shows $+H$ effect (hyperconjugation) due to presence of $\alpha$-chlorines.

Q.

Write the two chemical tests to distinguish ethyne and ethene

Q. Sulphur dioxide and SiCl4 has 1 lone pair and 2 bond pairs.
But I am not able to calculate it using the formula 1/2[V+L+A-C] . Can I please get help?

Q.

How can I distinguish the functional group region and fingerprint region in an infrared spectrum?

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. Stability order of the following compounds is:

1. $\left(I\right)>\left(II\right)>\left(IV\right)>\left(III\right)$
2. $\left(I\right)>\left(III\right)>\left(IV\right)>\left(II\right)$
3. $\left(II\right)>\left(III\right)>\left(IV\right)>\left(I\right)$
4. $\left(IV\right)>\left(II\right)>\left(I\right)>\left(III\right)$

Q.

Heat of hydrogenation of cyclohexane is -119KJ and heat of hydrogenation of benzene is 206KJ/mole. Find the resonance energy of benzene.

Q.

Why there is no Hyperconjugation in Carbanion?

Q. Write the structure of 4-chloropentan-2-one.

Q. Why do alkynes under go nucleophilic addition reaction . while alkynes don't do so.

Q.

The arrangement of ${\left(C{H}_3\right)}_{3}C-$, ${\left(C{H}_3\right)}_{2}CH-$ , $C{H}_{3}C{H}_2-$ when attached to a benzene or an unsaturated group in increasing order of inductive effect effect is.

Q.

The correct order of stability for the following alkoxides is:

1. (C) > (A) > (B)

2. (C) > (B) > (A)

3. (B) > (A) > (C)

4. (B) > (C) > (A)

Q.

Give the condition for hyperconjugation?

Q.

Which of the following alkyl group has the maximum hyperconjugation effect and least +I effect?

1. (CH₃)₂CH

2. CH₃CH₂ -

3. CH_3-

4. (CH₃)₃C-

Q. Which of the following is the correct order of electron density on the benzene ring in the following compounds?

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

Q.

In which of the following carbocation, there is maximum stabilization due to the hyperconjugation effect?

1. Neopentyl

2. Tert-Butyl

3. Isopropyl

4. Ethyl

Q.

Explain why alkyl groups act as electron donors when attached to a π system.

Q. Which of the following dienes would be the most stable?

1. 
2. 
3. 
4. 

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.