Question

Determine the hybridization and geometry of carbon in ethyne \((C_2H_2)\).

• A. \(sp^3\), Tetrahedral
• B. \(sp^2\), Trigonal planar
• C. \(sp\), Linear
• D. \(sp^3d\), Trigonal bipyramidal

Hint:

Hybridization shortcut: 2 regions → \(sp\) (linear) 3 regions → \(sp^2\) (trigonal planar) 4 regions → \(sp^3\) (tetrahedral)

Answer 1

The Correct Option is C

Concept: Hybridization describes the mixing of atomic orbitals to form equivalent hybrid orbitals. The type of hybridization depends on the number of electron domains around the atom.

Step 1: Write the structure of ethyne. \[ H-C \equiv C-H \] Each carbon atom forms:
• One sigma bond with hydrogen
• One sigma bond with another carbon
• Two pi bonds in the triple bond

Step 2: Determine hybridization. Each carbon has two sigma bonds. \[ \text{Number of hybrid orbitals} = 2 \] Thus, the hybridization is \(sp\).

Step 3: Determine geometry. The geometry of \(sp\)-hybridized carbon is linear with bond angle: \[ 180^\circ \] Hence, carbon in ethyne has \(sp\) hybridization and linear geometry.