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
describe addition polymerisation as exemplified by poly(ethene) and poly(chloroethene), PVC
(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 the following reactions of alkenes: (a) the electrophilic addition of (i) hydrogen in a hydrogenation reaction, \( H_2(g) \) and Pt/Ni catalyst and heat (ii) steam, \( H_2O(g) \) and \( H_3PO_4 \) catalyst (iii) a hydrogen halide, \( HX(g) \), at room temperature (iv) a halogen, \( X_2 \) (b) the oxidation by cold dilute acidified \( KMnO_4 \) to form the diol (c) the oxidation by hot concentrated acidified \( KMnO_4 \) leading to the rupture of the carbon–carbon double bond and the identities of the subsequent products to determine the position of alkene linkages in larger molecules (d) addition polymerisation exemplified by the reactions of ethene and propene
