Jamb Chemistry 1997 Past Questions and Answers

Question 21:

• JAMB 1997

How many Faraday of electricity are required to deposit 0.20 mole of nickel, if 0.10 Faraday of electricity deposited 2.98g of nickel during electrolysis of its aqueous solution?
(Ni = 58.7, 1F = 96 500 C mol^-)

A. 0.20
B. 0.30
C. 0.40
D. 0.50

Question 22:

• JAMB 1997

What is the oxidation number of Z in K₃ZCl₆?

A. -3
B. +3
C. -6
D. +6

Question 23:

• JAMB 1997

2H₂S_(g) + SO_2(g) + H₂O_(I) → 3S_(s) + 3H₂O_(I)..........(i) 3CuO_(s) + 2NH_3(g) → 3Cu_(s) + 3H₂O_(I) + N_2(g).........(II) In the equations above, the oxidizing agent (I) and the reducing agent in (II) respectively are?

A. H₂S _{and NH[sub]3}[/sub]
B. SO₂ and CuO
C. SO₂ and NH₃
D. H₂S _{and CuO}

Question 24:

• JAMB 1997

2SO_2(g) + O_2(g) 2SO₃. In the reaction above, the standard heats of formation of SO_2(g) and SO_3(g) are -297 KJ mol^-1 respectively. The heat change of the reaction is?

A. -99 kJ mol^-
B. -198 kJ mol^-
C. +198 kJ mol^-
D. +683kJ mol^-

Question 25:

• JAMB 1997

If the rate law obtained for a given reaction is rate = k(X)ⁿ (Y)^m, what is the overall order of the reaction?

A. Nm
B. N/m
C. N + m
D. N - m