Match List - I with List - II and select the correct answer using the code given below the Lists : List - I List - II (Compound/Molecule) (Shape of Molecule) I. CH3F 1. Trigonal planar II. HCHO 2. Tetrahedral III. HCN 3. Trigonal pyramidal IV. NH3 4. Linear Code : I II III IV

The molecular geometry of the given compounds is determined by VSEPR theory, which minimizes electron pair repulsion. I. CH3F (Fluoromethane) has four bonding pairs around the central carbon atom, resulting in a tetrahedral shape. II. HCHO (Formaldehyde) contains a central carbon double-bonded to oxygen and single-bonded to two hydrogens; these three electron groups arrange themselves in a trigonal planar geometry. III. HCN (Hydrogen Cyanide) features a triple bond between carbon and nitrogen and a single bond to hydrogen, creating two electron domains that result in a linear shape. IV. NH3 (Ammonia) has three bonding pairs and one lone pair on the nitrogen atom. While the electron geometry is tetrahedral, the presence of the lone pair results in a trigonal pyramidal molecular shape. Matching these gives the sequence 2-1-4-3.