To classify the given molecules as polar or nonpolar, we must consider their molecular geometry and the electronegativity differences between the atoms within the molecules.
- a) CH3Cl (Chloromethane): This molecule is polar. The chlorine atom is more electronegative than hydrogen, causing a dipole moment, as the electron density shifts towards the chlorine, creating a partial negative charge.
- b) H2O (Water): Water is a well-known polar molecule. The bent shape of the water molecule and the significant electronegativity difference between hydrogen and oxygen create a strong dipole moment, resulting in distinct partial charges.
- c) BCl3 (Boron Trichloride): BCl3 is nonpolar. Despite the difference in electronegativity between boron and chlorine, the symmetrical trigonal planar shape of the molecule causes the dipoles to cancel out.
- d) HF (Hydrogen Fluoride): HF is a polar molecule. The high electronegativity of fluorine compared to hydrogen results in a significant dipole moment, with fluorine holding a partial negative charge and hydrogen a partial positive charge.
- e) CCl4 (Carbon Tetrachloride): CCl4 is nonpolar. While there is a polarity due to the electronegativity difference between carbon and chlorine, the symmetrical tetrahedral shape allows the dipoles to cancel each other out.
- f) H2 (Hydrogen Gas): H2 is nonpolar. Both hydrogen atoms have the same electronegativity, leading to an even distribution of electron density and no dipole moment.
In summary, the classification of the molecules is as follows:
- Polar: CH3Cl, H2O, HF
- Nonpolar: BCl3, CCl4, H2