Question

How would you draw the most stable conformation of trans-1-ethyl-3-methylcyclohexane?

Axial ethyl group on C-1, Axial methyl group on C-3
Axial ethyl group on C-1, Equatorial methyl group on C-3
Equatorial ethyl group on C-1, Axial methyl group on C-3
Equatorial ethyl group on C-1, Equatorial methyl group on C-3
Choices b and c are both correct
Choices a and d are both correct

How would you draw the most stable conformation of trans-1-chloro-2-fluorocyclohexane?

Axial chlorine on C-1, Axial fluorine on C-2
Axial chlorine on C-1, Equatorial fluorine on C-2
Equatorial chlorine on C-1, Axial fluorine on C-2
Equatorial chlorine on C-1, Equatorial fluorine on C-2
Choices b and c are both correct
Choices a and d are both correct

How would you draw the most stable conformation of trans-1-ethyl-3-methylcyclohexane? Axial ethyl group on C-1, Axial methyl group on C-3 o Axial ethyl group on C-1, Equatorial methyl group on C-3 O Equatorial ethyl group on C-1, Axial methyl group on C-3 Equatorial ethyl group on C-1, Equatorial methyl group on C-3 O Choices b and c are both correct O Choices a and d are both correct Submit Answer Tries 0/1 How would you draw the most stable conformation of trans-1-chloro-2-fluorocyclohexane? Axial chlorine on C-1, Axial fluorine on C-2 O Axial chlorine on C-1, Equatorial fluorine on C-2 Equatorial chlorine on C-1, Axial fluorine on C-2 O Equatorial chlorine on C-1, Equatorial fluorine on C-2 O Choices b and c are both correct O Choices a and d are both correct Submit Answer Tries 0/1

Answer 1

Answer:

1. Equatorial ethyl group on C-1, Axial methyl group on C-3

2. Equatorial Chlorine on C-1, Equatorial fluorine on C-2

Explanation:

Before answering the question we must know about what are axial and equatorial bonds. Which bonds are above the plane and bellow the plane.

Axial and equatorial bonds:

Red line = ansal boods Blue lines = equatorial bonds

Bonds above and bellow the plane:

. - These redlines represents the plane These are the bonds above the plane These are the bonds bellow the plane.

When bulkier group(bigger groups) are present in axial position that molecule will be less stable because the bigger groups will generate steric replusion with other groups hence, the energy of the molecule increases and therefore the stability decreases.

So, to determine the most stable conformer of tue given molecules we first need to look at the substituents of the cyclohexane and place the bulkier group at equatorial position. And that will be our most stable conformer.

Now lets look at the given molecules,

1.

Trans-1-ethyl-3-methylcyclohexane:

Here an ethyl group is at 1-position and a methyl group is at 3-position.

Trans means one group is above the plane and one group is bellow the plane.

Ethyl group is the bulkier group here so, ethyl group should be present at equatorial position.

Most stable conformer:

ethyl group is bwllow the plane and methyl group is above the plane(trans).

H3 [ Methyl group on (C-3) Is akial. Нес. [ Ethyl group on (0-1)] quatorcial

So, in the most stable conformer Equatorial ethyl group is on C-1 and Axial methyl group is on C-3.

2.

Trans-1-chloro-2-fluorocyclohexane.

Trans means one group should be present above the plane and one group should be present bellow the plane.

Here, Chlorine is present at 1-position and Fluorine is present at 2-position.

Chlorine is the bulkier group and should be at equatorial position.

Most stable conformer:

Chlorine is bellow the plane and fluroine is above the plane(trans).

quatorial flecoreine on 2 Equatorial chlorine on (-1]

So, in the most stable conformer the equatorial chlorine is on C-1 and equatorial fluorine is on C-2.