Melting Points COOH COOH stearic acid,mp 70C oleic acid,mp 4C Copyright2010 Pearson Prentice Hall,Inc. The cis double bond in oleic acid lowers the melting point by66°C. A cis double bond bends the molecule,so it cannot pack efficiently. -A trans double bond has less effect. Chapter 25 8 Chapter 25 8 Melting Points ▪ The cis double bond in oleic acid lowers the melting point by 66°C. ▪ A cis double bond bends the molecule, so it cannot pack efficiently. ▪ A trans double bond has less effect