Question

1) An sp hybridized central atom can be used to describe the bonding in

a) CH4 b) HCN c) H2CO d) H2S

2) Which molecule is non polar?

a) CCl4 b) HCl c) CF3Cl d) CHCl3 e) NH3

3) In which pair do both compounds exhibit predominantly ionic bonding?

a) SO2 and HCl b) KNO3 and CH4 c) NaF and MgO d) KCl and CO2

Answer 1

1) option B

In HCN the central atom C has sp hybridization and the molecule is linear in shap.e

methane CH4 has the central C with sp3 hybridisation and tetrahedral shape.

CH2O, formaldehyde has sp2 hybridiation on central carbon with trigonal planar shpae.

H2S has S with sp3 hybridisation , with moelcular shape of V (angular). It is due to the presence of two lone pairs of elecrons.

2) optionA

CCl4 is the non-polar molecule with sp3 hybridisation at central carbon atom and symmetric tetrahedral structure. The molecular symmetry cancels the polarity of individual bonds making it nonpolar.

H-Cl has polar covalent H-Cl bond.

CF3Cl and CHCl3 both have sp3 hybridisation , but the bond moments are not cancellled due to heteroatoms in the molecules.

NH3 is also polar with sp3 hybridisation of cetral N atom and the presence of lone pair on N atom accounts for the polarity of molecule.

Q3)

Option C

Both NaF and MgO have predominantly ionic bonding as they are formed between a metal of IA,IIA and VIA and VIIA groups.

In the pair SO2 and HCl both are covalent and polar compounds but not ionic. They are covelent as they are formed between two non-metal atoms.

KNO3 is ionic with K+ and NO3- ions , but CH4 is a complete covalent molcule (between two non-metals)

KCl is predominantly ionic but CO2 is completely covalent compound.