Exam Q 30

Question 1

Distinguish between intramolecular bonding and intermolecular forces

Answer 1

Intramolecular bonding is bonding that takes place within a molecule i.e. it holds the atoms together (covalent bonding and polar bonding)

Intermolecular forces are the forces of attraction that exist between molecules .i.e. van der Waals forces, dipole-dipole forces and hydrogen bonding

Question 2

Explain ____ in terms of intramolecular bonding or intermolecular forces or both:
The boiling point of hydrogen (20k) is significantly lower than that of oxygen (90.2k)

Answer 2

Hydrogen has fewer electrons than oxygen and is smaller. Hydrogen has weaker intermolecular forces

Question 3

Explain ____ in terms of intramolecular bonding or intermolecular forces or both:
Iodine has very low solubility in water

Answer 3

Iodine is a non-polar covalent molecule and water is a polar covalent molecule. The intermolecular forces between the two are very weak

Question 4

Explain ____ in terms of intramolecular bonding or intermolecular forces or both:
When a charged rod is held close to a thin stream of water flowing from a burette, the stream of water is deflected

Answer 4

Intramolecular bonding:

Water is polar, the charged rod attracts the opposite charge on the water molecule bending the stream of water