Which formula represents a nonpolar molecule containing polar covalent bonds?
(1) h2o (3) nh3
(2) ccl4 (4) h2

H2O and NH3 are polar molecules. H2 is a nonpolar molecule but the H-H bond is also nonpolar.
Therefore, the best choice is CCl4. Although the C-Cl bond is polar due to electronegativity differences, the molecule itself is nonpolar because the net dipole moments cancel out, given its tetrahedral molecular structure.