1 Predict the types of intermolecular forces that may act be

1. Predict the type(s) of intermolecular force(s) that may act between the molecules in these substances. a. CO b. NH c. HCl d. C,H 2. Based on your understanding of intermolecular forces, which substance in each of the pairs should have the higher boiling point? Give your reasoning. a. NF, NH b. NaCl, HCI c. CF. CHF d. Cl, C,H,l

Solution

1)

a) since the net dipole moment in CO2 is zero, therefore it has only dipersion forces.

b) NH3 has dispersion, hydrogen bonding(bacause of NH bond) and dipole dipole forces (because of the polar nature of the molecule)

c) HCl : it has dipersion and dipole - dipole forces.

d) C3H8 : only dispersion forces as there is no polar group present in the molecule.

2)

a) NH3 will have higher boiling point because of the presence of hydrogen bonding.

b) NaCl has higher bp baccause it has strong ionic attractions between the molecules.

c) CHF3 has higher boiling point than CF4 because there is net zero dipole moment in CF4, so it has no dipole dipole forces and hence low boiling point.

d) C2H5Cl has higher boiling point because it has strong dipole dipole forces and vanderwaal forces between the molecules. Where as Cl2 has only dispersion forces.