4.1 Types of Bonds

Question 1

exceptions to octet rule

Answer 1

boron, sulphur, beryllium, phosphorus

Question 2

isoelectronic

Answer 2

has the same number of electrons (atoms match up to number of electrons in a noble gas to be stable)

Question 3

Cohesive Forces

Answer 3

intermolecular forces that bind ‘like’ molecules to one another
E.g. polar molecules are attracted to one another due to their opposite ends
Nonpolar element will form a convex meniscus

Question 4

Adhesive Forces

Answer 4

intermolecular forces that bind a substance to a surface
Polar element will form a concave meniscus

Question 5

SURFACE TENSION

Answer 5

→ A measure of the inward forces that must be overcome in order to expand the surface area of a liquid and resist an external force
Strength decreases with increasing temperature
Stronger IMF = Stronger ST

Question 6

CAPILLARY ACTION

Answer 6

→ The rise of liquids up very narrow tubes, which is limited by adhesive and cohesive forces
Water: adhesive forces > cohesive forces → convex meniscus
Mercury: cohesive forces > adhesive forces → concave meniscus

Question 7

VISCOSITY

Answer 7

→ The resistance of a liquid to flow
High viscosity = thicker
Low viscosity = thinner
→ Decreases with increasing temperature
→ Increases with increasing pressure
High IMF = High V