JAMB - Chemistry (2005 - No. 13)
Which of the following are structural isomers?
propanoic acid and propan-1, 2-diol
Propanal and propanone
Ethanoic acid and propanoic acid
Ethan-1, 2-diol and ethanoic acid
Explication
Isomers are two or more compounds having the same molecular formula but different structural formula.
Among the options given, only propanal and propanone have the same number of C atoms, Hydrogen atoms and Oxygen atoms even though they have different structural formulas, their molecular formulas are the same, hence they are Isomers.
Propanal - CH\(_3\)CH\(_2\)CHO ⇒ C\(_3\)H\(_6\)O
Propanone - CH\(_3\)COCH\(_3\) ⇒ C\(_3\)H\(_6\)O