Covalent Bonding Questions

Covalent Bonding

Bonding Worksheet

Covalent Bonding Questions

1. Define the terms covalent bond and coordinate bond.
Answer
  • A covalent bond is when the orbitals of two atoms overlap so that they share one or more pairs of electrons.
  • A coordinate bond is a covalent bond where both electrons originate from one of the two atoms.
2. Draw the dot and cross diagrams, and the display formulae for the following molecules.
a) SiH4
Dot and cross diagram for SiH4 Display formula for SiH4
b) NH4+
Dot and cross diagram for NH4+ Display formula for NH4+
c) AlCl3
Dot and cross diagram for AlCl3 Display formula for AlCl3
d) SO42-
Dot and cross diagram for SO4 2- Display formula for SO4 2-
e) AlCl4
Dot and cross diagram for AlCl4- Display formula for AlCl4-
f) SF6
Dot and cross diagram for SF6 Display formula for SF6
g) Al2Cl6
Dot and cross diagram for Al2Cl6 Display formula for Al2Cl6
3. State all the examples above that contain coordinate bonds, and explain why they are able to form coordinate bonds.
Answer
  • NH4+, AlCl4 and Al2Cl6 are co-ordinately bonded.
  • They can all coordinate bond because there is an atom with a lone pair of electrons that can be donated, and an atom that has an empty orbital that can accept them.
4. State all the examples that do not follow the octet rule, and explain why those examples are able to do so.
Answer
  • SF6 and SO42- do not follow the octet rule because the central atom has more than 8 electrons in its outer shell.
  • They can do this because sulfur is in period 3. This means that its electrons are in the 3rd shell.
  • The 3rd shell includes the 3d orbitals, which can also be filled while bonding.
  • AlCl3 also does not follow the octet rule. This is because it only has three electrons of its own.