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 the extraction of iron from hematite in the blast furnace, including symbol equations for each step, limited to: (a) the burning of carbon (coke) to provide heat and produce carbon dioxide (b) the reduction of carbon dioxide to carbon monoxide (c) the reduction of iron(III) oxide by carbon monoxide (d) the thermal decomposition of calcium carbonate/limestone to produce calcium oxide (e) the formation of slag
Describe the transition elements as metals that: (a) have high densities (b) have high melting points (c) have variable oxidation numbers (d) form coloured compounds (e) often act as catalysts as elements and in compounds
Describe the general chemical properties of metals, limited to their reactions with: (a) dilute acids (b) cold water and steam (c) oxygen
