Lesson 4: inter molecular forces and their applications

Question 1

Intermolecular forces

Answer 1

• atomic mass is adding all the masses of the compound
• inter means between: intermolecular forces are forces that exist between molecules
• 3 types: dipole-dipole attractions, london dispersion forces, and hydrogen bonding forces of attraction.

Question 2

Intermolecular forces

Answer 2

• boiling increases as the molar mass of the compound increases
• Hydrogen bonding occurs when H is attached to N, O or F ; the attraction is the H bonding

Question 3

rank intermolecular forces strongest to weakest

Answer 3

1. hydrogen bonding o-h o-n o-f
2. dipole-dipole forces
3. London dispersion forces

Question 4

Bonding in solids: Ionic solids

Answer 4

• hard, brittle substances with high melting points
• soluble in water,
• cannot conduct electricity in the solid state but can in liquid state
• the electrostatic attraction between cations and anions keeps ionic solids together: ionic bond

Question 5

Metallic Solids

Answer 5

• shiny, flexible solids that are excellent conductors of heat and electricity
• low ionization energies (the energy required to remove an electron)
• has many empty orbitals

Question 6

Explain why calcium fluoride conducts electricity only when it is melted or dissolved in water.

Answer 6

because in both situations its ions seperated from the crystal and are free to move