Jamb Chemistry 1980 Past Questions and Answers

Question 6:

• JAMB 1980

A sample of an oxide of mercury weighed 1.00g. When this was heated, oxygen was given off, and 1.00g of mercury metal only was left. What is the formula of the oxide?

A. Hg₂O
B. HgO₂
C. HgO₂
D. HgO
E. None of the above

Question 7:

• JAMB 1980

On heating, under suitable conditions, 1 litres of monoatomic gas,X, combines with 1¹/₂ litres of an oxide, What is the formula of the oxide.

A. XO₃
B. X₂O₃
C. X₃O₂
D. XO₂
E. None of the above

Question 8:

• JAMB 1980

If 1 litre of 2.2M sulphuric acid is poured into a bucket containing 10 litre of water,and resulting solution mixed thoroughly, the resulting sulpuric acid concentration will be?

A. 2.2 M
B. 1.1 M
C. O.22 M
D. 0. 11 M
E. 0.20 M

Question 9:

• JAMB 1980

Which of the following reactions is correct as as written?

A. FeCl₂ + 3NH₄OH → Fe(OH)₃ + 3NH₄Cl
B. Pb₂O₃ + 4HCl → PbCl₂ + 2H₂O
C. PbNO₃ + H₂S → PbS + 2HNO₃
D. NaOH + H₂SO₄ → NaHSO₄ +H₂O
E. 2NH₄NO₃ → N₂ + 2H₂O

Question 10:

• JAMB 1980

Under high pressure, real gases do not obey gas laws because their molecules?

A. Have become more energetic
B. Have become less energetic
C. Have become smaller in size
D. Decompose into atoms
E. Start repelling each other