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, explain, and write equations for, the acid/base behaviour of the oxides Na₂O, MgO, Al₂O₃, P₄O₁₀, SO₂ and SO₃ and the hydroxides NaOH, Mg(OH)₂ and Al(OH)₃ including, where relevant, amphoteric behaviour in reactions with acids and bases (sodium hydroxide only)
deduce the presence of a CH\(_3\)CH(OH)- group in an alcohol, CH\(_3\)CH(OH)-R, from its reaction with alkaline I\(_2\)(aq) to form a yellow precipitate of tri-lodomethane and an ion, \( RCO_2^-\)
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: \(NO_3^-\), \(CO_3^{2-}\), \(SO_4^{2-}\), \(OH^-\), \(NH_4^+\), \(Zn^{2+}\), \(Ag^+\), \(HCO_3^-\), \(PO_4^{3-}\)
