Jamb Chemistry 1999 Past Questions and Answers

Question 21:

• JAMB 1999

The entropy and enthalpy of a system are a measure of

A. Degree of disorderlinesss and heat content respectively
B. Heat content and degree of disorderliness respectively
C. Heat content of a system only
D. Degree of disorderliness only

Question 22:

• JAMB 1999

2SO_2(g) + O_2(g) ↔ 2SO_3(g). In the chemical reaction above, the substance that will increase the rate of production of sulphur (VI) oxide is

A. Manganese (IV) oxide
B. Finely divided iron
C. Vanadium (V) oxide
D. Nickel

Question 23:

• JAMB 1999

N₂O_4(g) ↔ 2NO_2(g). Increase in total pressure of the equilibrium reaction above will

A. Produce more of NO_2(g) in the mixture
B. Convert all of N₂O_4(g) to NO_2(g)
C. Have no effect on the concentrations of NO_2(g)and N₂O_4(g)
D. Produce more of N₂O_4(g) in the mixture

Question 24:

• JAMB 1999

What quantity of electricity will liberate 0.125 mole of oxygen molecules during the electrolysis of dilute sodium chloride solution?
[ F = 96 5000 C mol^-1 ]

A. 24 125 coulombs
B. 48 250 coulombs
C. 72 375 coulombs
D. 96 500 coulombs

Question 25:

• JAMB 1999

X + Y → Z. The rate equation for the chemical reaction above is ((-Δ[x])/Δt) = K[X]²[Y].
The overall order of the reaction is

A. 0.0
B. 1.0
C. 2.0
D. 3.09