Resonance Effect

Q. The compound that is the most difficult to protonate is:

1. $H_{2}O$
2. $H_{3}C-OH$
3. $H_{3}C-O-C{H}_3$
4. $Ph-OH$

Q. Arrange the following in increasing order of stability

$\text{(A)}(C{H}_3{)}_2\stackrel{\oplus }{C}-C{H}_{2}C{H}_3$
$\text{(B)}(C{H}_3{)}_3-\stackrel{\oplus }{C}$
$\text{(C)}(C{H}_3{)}_2-\stackrel{\oplus }{C}H$
$\text{(D)}C{H}_3-\stackrel{\oplus }{C}{H}_2$
$\text{(D)}\stackrel{\oplus }{C}{H}_3$

1. $A<E<D<C<B$
2. $E<D<C<B<A$
3. $D<E<C<A<B$
4. $E<D<C<A<B$

Q. Which will be the least stable resonating structure?

1. 
2. 
3. 
4. 

Q. Strength of acidity is in order:

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

Q. Which carbocation is the most stable?

1. 
2. 
3. 
4. 

Q. What is the correct order of stability of the following resonating structures?

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

Q. Select the incorrect statement regarding resonance effect.

1. Also known as Mesomeric effect $\left(M\right)$
2. Permanent effect
3. Distance independent effect
4. Distance dependent effect

Q. Resonance occurs due to

1. delocalisation of $\pi$-electrons
2. delocalisation of $\sigma$-electrons
3. delocalisation of lone pair
4. (a) and (c) above.

Q. The correct statement(s) concerning the structures E, F and G is/are

1. E, F and G are resonance structures
2. E, F and E, G are tautomers
3. F and G are geometrical isomers
4. F and G are chain isomers

Q. Which one of the following effect is shown by phenyl group?

1. +M
2. -M
3. (a) and (b) above.
4. None of the above

Q. Compare the stability of the given resonating structures :

1. Structure A is less stable than structure B
2. Structure A is more stable than structure B
3. Structure A and structure B are equally stable
4. Cannot comment about stability.

Q. Compare the relative stability of the following resonating structures:

1. (i) > (ii) > (iii)
2. (ii) > (i) > (iii)
3. (i) > (iii) > (ii)
4. (ii) > (iii) > (i)

Q. During resonance , the electrons are transferred from

1. A multiple bonds to an atom
2. A multiple bonds to a single covalent bond
3. An atom with a lone pair to the adjacent single covalent bond
4. All of the above.

Q. Which of the following is not true regarding resonance?

1. Resonance effect is temporary effect
2. Resonance occurs due to delocalisation of $\pi$-electrons
3. Resonating structures have same number of paired and unpaired electrons.
4. Resonating structures have identical positions of nuclei.

Q. Which of the following resonating structures of 1-methoxy-1, 3-butadiene is least stable?

1. $\stackrel{\ominus }{C}{H}_2-CH=CH-CH=\stackrel{\oplus }{O}-C{H}_3$
2. $C{H}_2=CH-\stackrel{\ominus }{C}H-CH=\stackrel{\oplus }{O}-C{H}_3$
3. $\stackrel{\ominus }{C}{H}_2-\stackrel{\oplus }{C}H-CH=CH-O-C{H}_3$
4. $C{H}_2=CH-\stackrel{\ominus }{C}H-\stackrel{\oplus }{C}H-O-C{H}_3$

Q. In which of the following resonance will be possible?

1. $C{H}_3-C{H}_2-C{H}_2-CHO$
2. $C{H}_2=CH-CH=O$
3. $C{H}_{3}COC{H}_3$
4. $C{H}_2=CH-C{H}_2-CH=C{H}_2$

Q.

The correct order of stability for the following species is:

1. (II) > (IV) > (I) > (III)

2. (I) > (II) > (III) > (IV)

3. (I) > (III) > (IV) > (II)

4. (I) > (III) > (II) > (IV)

Q. Choose the correct order of electron density for the following compounds :

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

Q. Choose the correct statement(s) regarding resonance effect.

1. It is a permanent effect.
2. Polarity is developed by delocalisation of $\sigma$ bonds.
3. It is independent of distance.
4. It is distance dependant

Q. Correct stability order of resonating structure is:
(i)
(ii)

(iii)

(iv)

1. (i)>(iii)>(ii)>(iv)
2. (ii)>(iii)>(iv)>(i)
3. (ii)>(i)>(iii)>(iv)
4. (i)>(iii)>(ii)>(i)

Q. The correct stability order of the given resonating structures is :

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 group(s) is/are only meta-directing?

1. $-Cl$
   
2. $-CH=C{H}_2$
   
3. $-CHO$
   
4. $-COOH$

Q. The correct order of the stability for the given carbanions is:

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

Q. Choose the correct statement for the following resonating structures :

1. Structure I is more stable than structure II
2. Structure I is less stable than structure II
3. Structure I and structure II are equally stable.
4. None of the above

Q. Predict the order of electron density for the following compounds :

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

Q. Which of the following is not an example of cross-conjugation?

1. 
2. 
3. 
4. 

Q. The stability order of the following carbocations is :

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

Q. Choose the correct conditions for the Resonance.

1. Must be planar structure
2. Interconvertible bond pairs and lone pairs
3. Same number of paired and unpaired electron in each Resonating structure
4. All of the above.

Q. Identify the type of conjugation in the benzene molecule.

1. $\pi$ bond - $\pi$ bond
2. $\pi$ bond - vacant orbital
3. $\pi$ bond - unshared pair of electron
4. $\pi$ bond - free radical

Q. For the given compounds the correct order of resonance energy is:

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