Older MCQs might not have the typical A, B, C,
D
choices. They
have choices 1, 2, 3, and a combination of them is the answer. Below is the key that maps such
combinations to the answer.
A
1, 2 and 3 are correct
B
1 and 2 only are correct
C
2 and 3 only are correct
D
1 only is correct
(a) describe covalent bonds in terms of orbital overlap giving σ and π bonds: - σ bonds are formed by direct overlap of orbitals between the bonding atoms - π bonds are formed by the sideways overlap of adjacent p orbitals above and below the σ bond (b) describe how the σ and π bonds form in molecules including H\(_2\), C\(_2\)H\(_6\), C\(_2\)H\(_4\), HCN and N\(_2\) (c) use the concept of hybridisation to describe sp, sp\(^2\) and sp\(^3\) orbitals
describe and explain the shape of, and bond angles in, molecules containing sp, sp\(^2\) and sp\(^3\) hybridised atoms
use the differences in Pauling electronegativity values to predict the formation of ionic and covalent bonds (the presence of covalent character in some ionic compounds will not be assessed) (Pauling electronegativity values will be given where necessary)
