Question

Which of the following is a ring chain of i-butene?

C. Both A and B
D. none of these

Answer 1

The molecules having the same molecular formula but a different arrangement of atoms are known as isomers. We will determine the molecular formula of each given compound to determine whether it is an isomer of i-butene or not. To determine the molecular formula we will count the number of each type of atom.

Complete solution:
The structure of i-butene is as follows:

i-butene has four carbon atoms and eight hydrogen atoms. So, the molecular formula of i-butene is ${{\text{C}}_{\text{4}}}{{\text{H}}_{\text{8}}}$ .
As we knew the isomers have same molecular formula so, we will determine the molecular formula of compound A and B as follows:
The structure of the given compounds A and B is as follows:

Compound A has four carbon atoms and eight hydrogen atoms. So, the molecular formula of compound A, cyclobutane is ${{\text{C}}_{\text{4}}}{{\text{H}}_{\text{8}}}$ .
Compound B also has four carbon atoms and eight hydrogen atoms. So, the molecular formula of compound B, is ${{\text{C}}_{\text{4}}}{{\text{H}}_{\text{8}}}$ .
So, as the molecular formula of compound A and B is the same as of i-butene so, compound A and B are the isomers of i-butene.
So, A and B both are the ring chain of i-butene.
Therefore, the correct answer is (A).

Note: Isomers have the same molecular formula but different chemical formula. A molecular formula shows the total number of an atom in the compound. The chemical formula shows the different groups of atoms of a molecule. To draw the structure of the isomers from the given molecular formula first we determine the degree of unsaturation by using the following formula: