Jamb Chemistry 2006 Past Questions and Answers

Question 41:

• JAMB 2006

In which of the following is the oxidation number of sulphur equal to -2?

A. SO₃
B. S₈
C. H₂S
D. SO₂

Question 42:

• JAMB 2006

In the electrolysis of CuSO_4(g) using platinum electrodes, the reaction at the anode is

A. 4H⁺ + 4e^- → 2H₂
B. 4OH^- - 4e^- → 2H₂O + O₂
C. 2OH - 2e^- → 2OH
D. 2OH^- + 2OH^- → 2H₂O + O₂

Question 43:

• JAMB 2006

Na2CO3(g) + 2HCl(aq) → 2NaCl(aq) + H2O(l) + CO2(g)
How many moles of sodium trioxocarbonate (IV) are there in a 25 cm3 solution which required 10cm3 of 0.05 mol dm-3 hydrochloric acid solution to neutralize it?

A. 1.000 mole
B. 0.100 mole
C. 0.010 mole`
D. 0.111 mole

Question 44:

• JAMB 2006

If the heat of combustion of hydrogen is -285.8kJ,
What is the heat of formation of water?

A. +571.6 kJ
B. -571.6 kJ
C. -285.8 kJ
D. +285.8 kJ

Question 45:

• JAMB 2006

5SO_2(g) + 2KMnO_4(aq) + 2H₂O_(l) → K₂SO₄ + 2MnSO_4(aq) + 2H₂SO_4(aq)
In the reaction above, the products give a

A. Purple solution
B. Purple precipitate
C. Colourless precipitate
D. Colourless solution