Question

Assertion: n-butane and iso-butane are examples
of isomers
Reason : isomerism is possible only with
hydrocarbons having 4 or more carbon atoms​

Answer 1

Answer:

Note : In the following questions a statement of assertion followed by a statement of

reason is given. Choose the correct answer out of the following choices.

(i) Both assertion and reason are true and the reason is the correct explanation of assertion.

(ii) Both assertion and reason are true and the reason is not the correct explanation of

assertion.

(iii) Assertion is true but the reason is false.

(iv) Assertion

Answer 2

Assertion: n-butane and iso-butane are examples

of isomers

Reason: Isomerism is possible only with

hydrocarbons having 4 or more carbon atoms

Assertion is correct but reason is false.

• Isomers are the compounds having same molecular formula but different physical properties. This phenomenon is termed as Isomerism.
• Both n-butane and isobutane have molecular formula C₄H₁₀ But they have different lengths of carbon chains i.e. chain of 4 carbons in n-butane and of 3 carbons in isobutane.
• Due to this difference in chain length, they are chain isomers.
• Chain Isomerism, specifically, is found only in hydrocarbons having 4 or more carbon atoms.
• But other types like positional isomers, tautomers can also be found in hydrocarbons with less than four carbon atoms.