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 tests to identify the gases: (a) ammonia, NH3, using damp red litmus paper (b) carbon dioxide, CO2, using limewater (c) chlorine, Cl2, using damp litmus paper (d) hydrogen, H2, using a lighted splint (e) oxygen, O2, using a glowing splint (f) sulfur dioxide, SO2, using acidified aqueous potassium manganate(VII)
Describe acids and alkalis in terms of their effects on: (a) litmus (b) thymolphthalein (c) methyl orange
Describe the properties of alkanes as being generally unreactive, except in terms of combustion and substitution by chlorine