Answer:
See explanation
Step-by-step explanation:
When we look at SO3 we will notice that the compound is trigonal planar and it is symmetric. This means that it has equal charge distribution hence its dipoles cancel out resulting in a zero net dipole moment.
However, COH2 is also trigonal planar but is non-symmetric. Hence, its dipole moments do not cancel out, hence the molecule has a resultant dipole moment and is a polar molecule