Question

draw the lewis structure of hydrogen cyanide (hcn) and then determine the hybridization of the central atom.

Explanation:

Step1: Calculate the total number of valence electrons

Hydrogen has 1 valence electron, carbon has 4 valence electrons, and nitrogen has 5 valence electrons. So, \(1 + 4+5 = 10\) valence electrons.

Step2: Draw the Lewis structure

Carbon is the central atom. Hydrogen forms a single bond with carbon (\(C - H\), using 2 electrons). Carbon forms a triple bond with nitrogen (\(C\equiv N\), using 6 electrons). There are \(10-(2 + 6)=2\) electrons left, which are placed as a lone - pair on nitrogen.

Step3: Determine the hybridization of the central atom (carbon)

Carbon has 2 electron - groups (one \(C - H\) single bond and one \(C\equiv N\) triple bond). According to the VSEPR (Valence - Shell Electron - Pair Repulsion) theory, the hybridization of an atom with 2 electron - groups is \(sp\).

Answer:

C. \(sp\)