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
deduce the molecular and/or empirical formula of a compound, given its structural, displayed or skeletal formula
write formulas of ionic compounds from ionic charges and oxidation numbers (shown by a Roman numeral), including: (a) the prediction of ionic charge from the position of an element in the Periodic Table (b) recall of the names and formulas for the following ions: \(NO_3^-\), \(CO_3^{2-}\), \(SO_4^{2-}\), \(OH^-\), \(NH_4^+\), \(Zn^{2+}\), \(Ag^+\), \(HCO_3^-\), \(PO_4^{3-}\)
describe: (a) the redox reaction with reactive metals to produce a salt and H\(_2\)(g) (b) the neutralisation reaction with alkalis to produce a salt and H\(_2\)O(l) (c) the acid–base reaction with carbonates to produce a salt and H\(_2\)O(l) and CO\(_2\)(g) (d) esterification with alcohols with concentrated H\(_2\)SO\(_4\) as catalyst (e) reduction by LiAlH\(_4\) to form a primary alcohol
