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, ( NH_3 ), using damp red litmus paper (b) carbon dioxide, ( CO_2 ), using limewater (c) chlorine, ( Cl_2 ), using damp litmus paper (d) hydrogen, ( H_2 ), using a lighted splint (e) oxygen, ( O_2 ), using a glowing splint (f) sulfur dioxide, ( SO_2 ), using acidified aqueous potassium manganate(VII)
Describe the reactions, if any, of: (a) potassium, sodium and calcium with cold water (b) magnesium with steam (c) magnesium, zinc, iron, copper, silver and gold with dilute hydrochloric acid and explain these reactions in terms of the position of the metals in the reactivity series
