Module 2

Question 1

principal quantum number

Answer 1

shell number/energy level

Question 2

shapes of orbitals in s and p subshells

Answer 2

s: sphere
p: dumbbell

Question 3

why are ionic compounds generally soluble in polar solvents?

Answer 3

• ion-dipole interactions between ions and polar molecules are stronger than the ionic bonds between ions
• therefore the ionic lattice breaks down and polar molecules surround the ions

(energy released in the formation of ion-dipole interactions is greater than the energy required to break ionic bonds)

Question 4

how do ionic compounds act as electrical conductors when molten or aqueous?

Answer 4

ions act as mobile charge carriers

Question 5

ionic vs covalent bonds

Answer 5

ionic:
- attracts in all directions (in three dimensions)
- stronger

covalent:
- localised attraction (solely between shared pair of e- and nuclei of bonding atoms)
- weaker

Question 6

which periods can expand their octet?

Answer 6

period 3+

Question 7

electronegativity

Answer 7

the ability of an atom to attract an e- pair in a covalent bond

Question 8

why is a molecule polar? (2 marks)

Answer 8

• difference in electronegativity between atom A and atom B causes a dipole
• the dipoles are assymetrical/do not cancel out

Question 9

factors affecting IMF strength between inorganic molecules

Answer 9

• number of e-
• charge of atoms in molecule

Question 10

state and explain two anomalous properties of ice. (4 marks)

Answer 10

• ice is less sense than water
  –> H bonds between water molecules form an open lattice structure
• ice has a relatively high melting point
  –> strong H bonds require a lot more energy to overcome

Question 11

two types of isomerism

Answer 11

• structural
• stereoisomerism

Question 12

types of structural isomerism

Answer 12

• branched
• positional
• functional

Question 13

types of stereoisomerism

Answer 13

• cis/trans
• E/Z
• optical

Question 14

what is meant by the term weighted mean mass

Answer 14

mean average mass taking into account the abundance of the isotopes

Question 15

order molecular structures from highest to lowest melting/boiling point

Answer 15

• giant covalent
• metallic
• ionic
• simple covalent

Question 16

define electronegativity

Answer 16

a measure of attraction of an atom in a bonded pair for the pair of electrons in a covalent bond

Question 17

define electron affinity

Answer 17

the ability of an atom to accept an electron

e- + X –> X-