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 the properties of alkanes as being generally unreactive, except in terms of combustion and substitution by chlorine
Describe acids and alkalis in terms of their effects on: (a) litmus (b) thymolphthalein (c) methyl orange