Explain the structure hybridization and bond angle of CH4, NH3, and H2O.
The Correct Answer and Explanation is:
The structure, hybridization, and bond angles of CH4, NH3, and H2O can be explained by considering their molecular geometries and the number of electron pairs around the central atom.
CH4 (Methane)
- Hybridization: In methane, the central carbon atom forms four sigma bonds with four hydrogen atoms. This requires the carbon to have sp³ hybridization, where one s orbital mixes with three p orbitals, creating four equivalent hybrid orbitals.
- Geometry: The molecular shape of CH4 is tetrahedral, where the four bonds are arranged symmetrically.
- Bond Angle: The bond angle in CH4 is 109.5° because of the symmetrical tetrahedral geometry, ensuring minimal repulsion between bonding pairs.
NH3 (Ammonia)
- Hybridization: In ammonia, nitrogen has three single bonds with hydrogen atoms and one lone pair of electrons. The nitrogen atom undergoes sp³ hybridization, where one s orbital mixes with three p orbitals. The lone pair occupies one of these hybrid orbitals.
- Geometry: The molecular shape of NH3 is trigonal pyramidal because the lone pair causes a distortion from the ideal tetrahedral geometry.
- Bond Angle: The bond angle in NH3 is slightly reduced from the ideal tetrahedral angle, at 107°, due to the lone pair repulsion which compresses the bond angle between the hydrogen atoms.
H2O (Water)
- Hybridization: In water, the oxygen atom forms two single bonds with hydrogen atoms and has two lone pairs of electrons. The oxygen atom undergoes sp³ hybridization, where one s orbital combines with three p orbitals, with two hybrid orbitals occupied by lone pairs and two by bonding electrons.
- Geometry: The molecular shape of H2O is bent or angular. The lone pairs on oxygen push the hydrogen atoms closer together, resulting in this bent shape.
- Bond Angle: The bond angle in H2O is 104.5°, which is even smaller than NH3, due to the stronger repulsion from the lone pairs on oxygen.
In summary, CH4 has a tetrahedral structure with 109.5° bond angles, NH3 has a trigonal pyramidal structure with bond angles of 107°, and H2O has a bent structure with a bond angle of 104.5°, all due to their unique hybridization and lone pair repulsions.
