Conformational Isomerism

Q. Which of the following has zero dipole moment?

1. cis-2-butene
2. 1-butene
3. 2-methyl-1-propene
4. trans-2-butene

Q.

With respect to the conformers of ethane, which of the following statements is true?

1. Bond angle remains same but bond length changes

2. Bond angles changes but bond length remains same

3. Both bond angle and bond length change

4. Both bond angles and bond length remain same

Q. Which of the following pairs of compounds is a pair of enantiomers ?

1. 
2. 
3. 
4. 

Q.

The total number(s) of stable conformers with non-zero dipole moment for the following compound is (are)

1. 2

2. 4

3. 3

4. 5

Q. $HO-\underset{\left(3\right)}{C{H}_2}-\underset{\left(2\right)}{C{H}_2}-\stackrel{\stackrel{O}{||}}{\underset{\left(1\right)}{C}}-H$
Which conformer of above compound is most stable?
(Consider conformers across $C_2-C_3)$

1. Anti-staggered
2. Gauche
3. Fully eclipsed
4. Partially eclipsed

Q.

The total number of possible isomer for the complex compound [Cu(NH3)4] [PtCl4]

Q.

Name the type of isomerism to which geometrical and optical isomerism belong to.

Q. Explain with structure the number of geometrical and optical isomers in type [M(AA)3].

Q.

Which of the following is the correct order of stability of the following four distinct conformations of n-butane?

1. Staggered > Gauche >Partially eclipsed > Fully eclipsed

2. Gauche Staggered > Partially Eclipsed > Fully eclipsed

3. Staggered > Partially eclipsed > Gauche >Fully eclipsed

4. Fully eclipsed > Staggered >Partially eclipsed > Gauche

Q. What kind of geometrical isomerism exists for [M(AB)3] complex? (AB) is an unsymmetrical bidentate ligand

Q.

In the following structures, which two forms are straggered conformations of ethane

1. 1 and 4

2. 2 and 3

3. 2 and 4

4. 1 and 3

Q.

Water is a ______ solvent. (polar/nonpolar)

Q. How many lone pairs and bond pairs are present in H2SO4?

Q. Which of the following statement(s) is/are correct?

1. Cyclopropane has a non-planar structure.
2. Cyclobutane has a non planar structure.
3. Cyclopentane has a non planar structure.
4. Cyclopentane has a planar structure.

Q.

Which of the following has the minimum heat of dissociation?

1. [(CH₃)₃ N → B(CH₃)₃]

2. [(CH₃)₃ N → BF₃]

3. [(CH₃)₃ N → B(CH₃)F₂]

4. [(CH₃)₃ N → B(CH₃)₂ F]

Q.

(IE)1 and (IE) 2 of Mg are 740, 1540kJ mol- calculate the percentage of Mg⁺ and Mg²⁺ if 1g of Mg absorbs 50.0KJ of energy.

Q. Which of the following conformer represent the chair form of cyclohexane ?

1. 
2. 
3. 
4. 

Q. Which of the following will have meso-isomer ?

1. 2- chlorobutane
2. 2- hydroxyopanoic acid
3. 2, 3- dichloropentane
4. 2, 3- dichlorobutane

Q. Which of the following are pair of diastereomers?

1. (I) and (III)
2. (II) and (IV)
3. (I) and (II)
4. None

Q. Assertion :Staggered conformation of ethane is most stable while eclipsed conformation is least stable. Reason: Staggered form has the least torsional strain and the eclipsed form has the maximum torsional strain.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Which of the following is true regarding stability of eclipsed and staggered conformation?

1. Eclipsed conformation is more stable than staggered conformation
2. Eclipsed conformation is less stable than staggered conformation
3. Stability of eclipsed and staggered conformations are equal
4. None of the above

Q. Conformational isomers are due to :

1. Free rotation about C-C single bond
2. Frozen rotation about C-C double bond
3. Restricted rotation about C-C single bond
4. Free rotation about C-H single bond

Q. Why is it possible for conformers to interconvert at room temperature?

1. Because there is no energy difference between different conformer states.
2. Energy available at room temperature is sufficient.
3. Conformers are usually found only at high temperatures.
4. Conformers don't actually exist. They are a theoretical concept.

Q. Conformational isomerism can be exhibited by which of the following compounds?

1. Benzene at /(100^oC/)
2. Methane at room temperature
3. Cyclohexane at /(-100^oC/)
4. Ethane at room temperature

Q. Which of the following isomer is not considered, while counting total number of isomers of any molecule?

1. Chain isomer
2. Position isomer
3. Conformational isomer
4. Geometrical isomer

Q. When two different 3D arrangements in space of the atoms in a molecule are interconvertible by free rotation about the single bonds, they are called:

1. Conformational isomers
2. Ring chain isomers
3. Functional isomers
4. All of the above

Q. Which of the following may exhibit conformational isomerism?

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

Q. If two different 3D arrangements in space of the atoms in a molecule are interconvertible merely by free rotation about bonds, they are called _____

1. Conformational Isomer
2. Configurational Isomer
3. Strucutral Isomer
4. Otical isomerism

Q. Which of the following compound exhibit optical isomerism?

1. 
2. 
3. 
4. None of the above

Q. The rotational energy barrier $in{\text{K cal mol}}^{-1}$ between the most stable and the least stable conformations of $\text{2, 3- dimethylbutane}$ along $C_2-C_3$ bond is :
(Given : Energies ${\text{K cal mol}}^{-1}$ for $H/C{H}_3$ eclipsing = $1.8$, $C{H}_3/C{H}_3$ eclipsing = $3.9$, $C{H}_3/C{H}_3$ gauche = $0.9$. Torsional strain of $H/H$ eclipsing is neglected.)