Question

1. Mention the intermolecular forces present between

(a) water and alcohol (b) chlorine and carbon tetrachloride

© He and He atoms (d) Na+

ion and water

(e) HCl and H2O
​

Answer 1

Explanation:

a) Hydrogen bonding

b) Dispersion force

c) London Dispersion force

d) Ion-dipole

e) Dipole dipole interaction

Answer 2

Answer:

(a) dispersion forces, dipole-dipole attractions, and hydrogen bonding.

(b) Cl2 and CCl4 are non polar and do not have a dipole moment. The strongest intermolecular force is dispersion forces. Its strongest intermolecular forces are London dispersion forces.

(c) The intermolecular attractions in between two Helium atoms is very weak. The molecules will stick to each other to form a liquid only when the temperature is lower than 4 K or at -269°C. The answer is Hydrogen bonds and Dipole-Dipole forces.

(d) Ion-dipole interaction – occurs between an ion and a polar covalent compound. The ion here is Na+ while H2O is the polar covalent compound.

(e) Even though HCl has dispersion forces, they are overshadowed by dipole-dipole by far. If they were not, then HCl would not be soluble in water...

Since water hydrogen-bonds, the most fair trade in interaction energy would be from strong dipole-dipole interactions, not weak dispersion.