Hydrogen cyanide, HCN(g), is a toxic compound that can be generated in certain industrial processes. A safety report requires a rigorous representation of its molecular structure.
(a) Calculate the total number of valence electrons that must appear in a Lewis diagram for one molecule of HCN.
(b) Considering typical bonding preferences and atom electronegativities, choose a linear sequence for the three atoms and justify your choice.
(c) Construct a Lewis diagram that satisfies the octet (or duet) requirements for all atoms in HCN, explicitly showing all lone pairs and multiple bonds, if any.
(d) Determine the formal charge on each atom in the structure from part (c) and explain why that structure is considered the best representation of the molecule.