Question

predict the approximate molecular geometry of a formaldehyde molecule:
\ce{h_{2}c=\overset{\cdot \cdot}{o}}

the shape is:
\\(\bigcirc\\) tetrahedral
\\(\bigcirc\\) linear
\\(\bigcirc\\) trigonal pyramidal
\\(\bigcirc\\) trigonal planar
\\(\bigcirc\\) bent

Explanation:

1. Identify the central atom: In formaldehyde ($\text{H}_2\text{C=O}$), the central atom is carbon (C).
2. Count electron domains around C: It has 2 single bonds to H atoms, 1 double bond to O, and no lone pairs. This gives 3 total electron domains.
3. Match to molecular geometry: 3 electron domains with no lone pairs correspond to a trigonal planar geometry, where all atoms lie in a flat, triangular arrangement around the central carbon.

Answer:

trigonal planar