What are the molecular shapes of CCl4, CH3Cl, and CHCl3
The Correct Answer and Explanation is:
The molecular shapes of CCl4, CH3Cl, and CHCl3 can be understood by considering the electron pair geometry and the number of bonded atoms around the central atom in each molecule.
1. CCl4 (Carbon Tetrachloride):
- Molecular Geometry: Tetrahedral
- Explanation: Carbon in CCl4 is the central atom, and it is bonded to four chlorine atoms. According to the VSEPR theory (Valence Shell Electron Pair Repulsion), the four bonding pairs of electrons around the central carbon atom repel each other equally, resulting in a symmetrical tetrahedral shape. This shape minimizes electron pair repulsion, and the bond angles between the chlorine atoms are approximately 109.5°.
2. CH3Cl (Chloromethane):
- Molecular Geometry: Tetrahedral (with a slight distortion)
- Explanation: In CH3Cl, carbon is the central atom, and it is bonded to three hydrogen atoms and one chlorine atom. Since there are four bonding pairs of electrons around the central carbon, the electron geometry is tetrahedral, which is similar to CCl4. However, the presence of a chlorine atom, which is more electronegative than hydrogen, can cause a slight distortion in the shape. Despite this, the geometry remains tetrahedral with bond angles close to 109.5°, although they may be slightly altered due to the larger size and stronger electronegativity of chlorine.
3. CHCl3 (Chloroform):
- Molecular Geometry: Tetrahedral (slightly distorted)
- Explanation: Like CH3Cl, CHCl3 has a central carbon atom bonded to three chlorine atoms and one hydrogen atom. The electron geometry is again tetrahedral, as there are four bonded atoms around the central carbon. However, the molecular shape may be slightly distorted due to the varying electronegativities of chlorine and hydrogen. The bond angles in CHCl3 are close to 109.5°, though slight variations may exist due to the differences in atom size and electronegativity.
Summary:
- CCl4: Tetrahedral geometry with perfect symmetry.
- CH3Cl: Tetrahedral geometry with slight distortion due to chlorine’s electronegativity.
- CHCl3: Tetrahedral geometry with slight distortion due to the presence of chlorine atoms.
The common feature in all three molecules is the tetrahedral electron geometry, but the molecular shapes may show slight distortions due to the differences in electronegativity between hydrogen and chlorine.
