Question

Draw isomers of chloropentane Give name and classify as primary tertiary or secondary

Answer 1

Answer:

Structural Isomers – Just how many structures can you make from a simple formula?

1. methane: CH4

condensed formula

2D formula 3D formula

methane

2. ethane: C2H6

Once the two carbons are connected, there are only six additional bonding sites and these are filled by the

six hydrogen atoms. Ethane is a saturated molecule. C2H6 is completely unambiguous.

C2H6

condensed formula 2D formula

3D formula

You can twist about this single bond generating

different conformations. Build a model and try it.

condensed line formula

CH3CH3 ethane

The carbon-carbon single bond allows rotation of one group of three C-H sigma bonds past the other

group of three C-H sigma bonds. Using a molecular model of ethane, fix one carbon with one hand and

spin the other carbon with you other hand. The different arrangements of the atoms as they rotate past

one another are called conformations. Conformations are the result of differences in a structure from

rotation about single bonds. We will study conformations more in a later topic.

The three front bonds can rotate around

the carbon-carbon single bond, like spokes

on a wheel or propeller blades on an airplane.

A straight-on view shows the three bonds as lines connecting to the front carbon atom,

written as a small dot. The rear carbon is usually drawn as a large circle and the three

bonds to that carbon are also drawn as lines, but only down to the circle. Rotation of

the front bonds is easily seen in two different structures. These are called Newman

projections and we will see more of them later.

= rear carbon atom

= front carbon atom

In this drawing the bonds

on the front carbon are

rotated by 60o

relative to

bonds on the back carbon.

3. propane: C3H8

Once again, there is only one possible arrangement of the bonding atoms. The third carbon has to be

attached to either of the other two carbons forming a three carbon chain with eight additional bonding sites,

each bonded to a hydrogen atom. Propane is a saturated molecule. C3H8 is completely unambiguous.

Answer 2

Explanation:

To Do :-

1. Draw isomers of chloropentane
2. Classify them as 1°,2°,3° halide

Solution :-

There are 8 isomers of chloropentane :-

1. chloropentane (1°)
2. 1-chloro-2-methyl butane (1°)
3. 1-chloro-3-methyl butane (1°)
4. 2-chloropentane (2°)
5. 2-chloro-2-methyl butane (3°)
6. 2-chloro-3-methyl butane (2°)
7. 3-chloro pentane (2°)
8. 1-chloro-3,3-dimethyl propane (1°)

( Refer to the attachment. )

Additional information :-

Chain isomerism :-

• Compound having same molecular formula but differ in its carbon chain, are said to be chain isomers and phenomena is called chain isomerism.

Positional isomerism :-

• Compound having same molecular formula but differ in the position of functional group or substituent, are said to be positional isomers and phenomena is called positional isomerism.