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: (a) the complete and incomplete combustion of alkanes (b) the free-radical substitution of alkanes by \( Cl_2 \) or \( Br_2 \) in the presence of ultraviolet light, as exemplified by the reactions of ethane
state and explain the shapes of, and bond angles in, molecules by using VSEPR theory, including as simple examples: • BF\(_3\) (trigonal planar, 120°) • CO\(_2\) (linear, 180°) • CH\(_4\) (tetrahedral, 109.5°) • NH\(_3\) (pyramidal, 107°) • H\(_2\)O (non-linear, 104.5°) • SF\(_6\) (octahedral, 90°) • PF\(_5\) (trigonal bipyramidal, 120° and 90°)
