Jamb Chemistry 1981 Past Questions and Answers

Question 21:

• JAMB 1981

A polymerization reaction is one in which?

A. Small molecules form giant molecules
B. Atoms form molecules
C. Giant molecules form small molecules
D. Molecules form volatile compounds
E. A molecule rearranges itself

Question 22:

• JAMB 1981

Which of the following is the electronic configuration of sodium?
(Atomic number of Na = 11)

A. 1s² 2s²2p⁶ 3s²
B. 1s² 2s²2p⁶ 3s² 3p1s² 2s²2p⁶ 3s¹
C. 1s² 2s²2p⁶ 3s¹
D. 1s² 2s²2p⁶ 3s^°
E. 1s² 2s²2p⁶ 4s¹

Question 23:

• JAMB 1981

In the reaction of oxygen with hydrogen to produce water, which of the following statements is true?

A. One atom of hydrogen reacts with two atoms of oxygen to give one molecule of water
B. Two atoms of hydrogen react with two atoms of oxygen to give two molecules of water
C. One molecule of oxygen reacts with one molecule of hydrogen to give two molecules of water
D. One molecule of hydrogen reaccts with two molecules of oxygen to give three molecules of water
E. One molecule of oxygen reacts with two molecules of hydrogen to give two molecules of water

Question 24:

• JAMB 1981

Na₂CO₃ + 2HCI → 2NaCI + H₂O + CO₂. Using the above equation, what volume of carbondioxide, measured at s.t.p is liberated when 53g of sodium carbonate is dissolved in hydrochloric acid?
(1 mole of gas occupies 22.4 dm³ at s.t.p)
(Na = 23, C = 12, O = 16)

A. 44.8 dm³
B. 11.2 dm³
C. 100.1 dm³
D. 3.0 dm³
E. 22.4 dm³

Question 25:

• JAMB 1981

When sodium nitrate dissolves in water, ∆H is positive. This means that?

A. The reaction is catalysed
B. The reaction is complete
C. The reaction is exothermic
D. The reaction is endthermic
E. Sodium nitrate is highly soluble in water