Stability of Conformations

Q. Which conformer of the compound given below is the most stable?
$HO-C{H}_2-C{H}_2-F$

1. Staggered
2. Partially eclipsed
3. Gauche
4. Fully eclipsed

Q. Energy barrier between staggered and eclipsed conformation of ethane is

1. 12.6 kcal/mol
2. 12.6 KJ/mol
3. 6 KJ/mol
4. 16 KJ/mol

Q. Boat from of cyclohexane is less stable than chair form because:

1. it floats on water
2. of interaction of flag pole hydrogens on top of carbon
3. eclipsed $C-H$ bonds
4. of high dipole moment

Q. Which form is more stable among all these arrangements?

1. 
2. 
3. 
4. 

Q.

The rate constant for the decomposition of hydrocarbons is 2.418 × 10⁻⁵ s⁻¹ at 546 K. If the energy of activation is 179.9 kJ/mol, what will be the value of pre-exponential factor.

Q. Which one of the following carbocations is most stable?

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

Q. What is the major alkene formed in the following Hofmann elimination?

1. $C{H}_{3}CH=C{H}_2$
2. $C{H}_3-\underset{C{H}_2}{\underset{||}{C}}-C{H}_3$
3. $C{H}_{3}C{H}_{2}CH=C{H}_2$
4. $C{H}_3\underset{C{H}_3}{\underset{|}{CH}}CH=C{H}_2$
5. $C{H}_{3}C{H}_2\underset{C{H}_3}{\underset{|}{C}}=C{H}_2$

Q.

The rate constant for the decomposition of hydrocarbons is 2.418 × 10⁻⁵ s⁻¹ at 546 K. If the energy of activation is 179.9 kJ/mol, what will be the value of pre-exponential factor.

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

1. $C{H}_3-C{H}_2-C{H}_2^{\oplus }$
2. $C{H}_3-C{H}_2-C{H}_2-C{H}_2^{\oplus }$
3. $C{H}_3-C{H}^{\oplus }-C{H}_3$
4. $C{H}_3-C{H}_2-C{H}^{\oplus }-C{H}_3$

Q. Energy barrier between staggered and eclipsed conformation of ethane is

1. 12.6 kcal/mol
2. 12.6 KJ/mol
3. 6 KJ/mol
4. 16 KJ/mol

Q. Which conformer of the compound given below is the most stable?
$HO-C{H}_2-C{H}_2-F$

1. Staggered
2. Partially eclipsed
3. Gauche
4. Fully eclipsed

Q. Consider the following carbanions.
I)$C{H}_3-C{H}_2^{-}$
II)$C{H}_2=C{H}^{-}$
III)$CH\equiv \stackrel{-}{C}$
Correct order of stability of these carbanions in decreasing order is:

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

Q. The correct order of stability of conformation of $N{H}_2-C{H}_2-C{D}_2-OH$ is:

1. Gauche > Anti > Eclipsed
2. Anti > Gauche > Eclipsed
3. Anti = Gauche > Eclipsed
4. Gauche > Eclipsed > Anti

Q. Which form is more stable among all these arrangements?

1. 
2. 
3. 
4. 

Q. Energy barrier between staggered and eclipsed conformation of ethane is

1. 12.6 kcal/mol
2. 12.6 KJ/mol
3. 6 KJ/mol
4. 16 KJ/mol

Q. Energy barrier between staggered and eclipsed conformation of ethane is

1. 12.6 kcal/mol
2. 12.6 KJ/mol
3. 6 KJ/mol
4. 16 KJ/mol

Q. Which form is more stable among all these arrangements?

1. 
2. 
3. 
4.