Which of the following set constitutes of all the molecules and ions of non-planar geometry?

Explanation

The question asks for species that have NON-PLANAR geometry so, those structures which are planar are to be eliminated. Option A includes benzene and SO3, which are planar molecules as all carbons of benzene have trigonal planar geometry around them, while SO3 is a trigonal planar molecule as well (due to the presence of three bonding pairs of electrons around them). PH4+ and NH3 are not planar however, PH4+ is tetrahedral (its shape corresponds to ammonium ion as P and N are in the same group), while NH3 has a trigonal pyramidal shape (3 bonding pairs and one lone pair around N). Option B is correct, as all four substances have non-planar structures. CH4 and NH4+ have tetrahedral structures due to four pairs of bonding electrons around the central atom, MnO4- also has tetrahedral geometry (see pictures below), while NF3 has a trigonal pyramidal shape (compare it to NH3 structure as both have three single bonds with a lone pair of electrons). Option C is also incorrect, as ethene and BeCl2 are planar molecules. Ethene is trigonal planar, while BeCl2 is linear. H2O and H2S are non planar however, with both having the same bent structure with two bonding pairs of electrons and two lone pairs (the two structures are similar as both O and S belong to group 6). Option D is incorrect due to the presence of planar C2H4 (ethene), NO3-, and BF3, as they both are trigonal planar. SO2 only is the non-planar bent substance in this list.