Isomers

Question 1

Structural isomers

Answer 1

Have the same molecular formula and weight but different chemical and physical properties. They are also called constitutional isomers.

Question 2

Stereoisomers

Answer 2

Share same atom connectivity but differ in space as in wedges and dash. They can be conformation or configuration isomers

Question 3

Conformational isomers

Answer 3

They differ in rotation around single sigma bonds. The different rotations lead to different strains.

Question 4

Anti and staggered conformation

Answer 4

It is the most stable because there is less repulsion and less energy. The groups are 180 degrees from eachother.

Question 5

Gauche conformation

Answer 5

When the repulsive groups are 60 degrees from each other. This is less stable than anti and staggered conformation and has more energy than it too. It is more stable and has less energy than eclipsed.

Question 6

Totally eclipsed

Answer 6

When the most repulsive groups are on top of each other. This is the least favored and has the highest energy.

Question 7

Eclipsed

Answer 7

When the groups are on top of each other.

Question 8

Angle strain

Answer 8

Bond angles deviate from ideal when stretched or compressed

Question 9

Torsional strain

Answer 9

When cyclic molecules have to assume eclipsed or gauche

Question 10

Nonbonded or Van der Waals strain

Answer 10

Nonadjacent atoms or groups compete for same space

Question 11

Most stable to least stable cyclohexane conformations

Answer 11

Chair, twist boat, boat

Question 12

Axial

Answer 12

Perpendicular to plane

Question 13

Equatorial

Answer 13

Parallel to plane