Question

Draw and name all structural isomers formed by monochlorination of each alkane cyclopentane , CH3CH2CH2CH2CH3 , and (CH3)3CH?

Answer 1

See below.

Cyclopentane

The structure of cyclopentane is

All the H atoms are equivalent, so you get only one monochlorination product.

The product is chlorocyclopentane.

Pentane

Pentane has three non-equivalent hydrogen sites.

The methyl groups at each end of the chain are clearly different from all the rest.

Substitution of one of these `"H"` atoms will give 1-chloropentane.

The three `"CH"_2` groups split into two — the middle `"CH"_2` is different simply because it is in the middle.

Substitution of the middle `"CH"_2` with chlorine gives 3-chloropropane.

Finally, substitution of any of the remaining four `"CH"_2` hydrogen atoms gives 2-chloropropane.

2-Methylpropane

"We leave it as an exercise for the student" to answer this part.

Hint: there are two types of hydrogen atom.