Butane:C4H10 CH3CH2CH2CH3 n-butane CH3 CH3CHCH3 isobutane Constitutional isomers are compounds with the same molecular formula but the carbons are connected differently. 2013 Pearson Education,Inc. Chapter 3 5 © 2013 Pearson Education, Inc. Butane: C4H10 Constitutional isomers are compounds with the same molecular formula but the carbons are connected differently. CH3CH2CH2CH3 CH3CHCH3 CH3 n-butane isobutane Chapter 3 5