Chemistry 2011 JAMB Past Questions - Question 49: Which of the following statements is true about 2-methylpropane and butane?

Correct Answer

A

Explanation

The statement "They have different numbers of carbon atoms." is true.

2-methylpropane (also known as isobutane) has four carbon atoms, whereas butane has four carbon atoms as well. So, they both have the same number of carbon atoms.

However, they are not members of the same homologous series. Butane belongs to the alkane homologous series, while 2-methylpropane is a branched alkane.

They also do not have the same boiling points. Butane has a boiling point of -0.5°C, while 2-methylpropane has a boiling point of -11.7°C at standard pressure.

They do not have the same chemical properties either, as their structures and arrangements of atoms are different due to branching in 2-methylpropane.