Formic acid is an important starting material for some polymers. Its structure makes it useful for the synthesis of strong polymer chains. Account for the structure of a formic acid molecule, HCOOH, in terms of hybrid orbitals, bond angles, and σ- and π-bonds. The C atom is attached to an H atom, a terminal O atom, and an —OH group.

ANTICIPATE Because the C atom is attached to three atoms, you should anticipate that its hybridization scheme is sp² and that one unhybridized p-orbital remains.

PLAN Use the VSEPR model to identify the shape of the molecule and then assign the hybridization consistent with that shape. All single bonds are σ-bonds, and multiple bonds are composed of a σ-bond and one or more π-bonds. Finally, form σ- and π-bonds by allowing the orbitals to overlap.