Energy changes - Jamb Chemistry Past Questions and Answers

Question 6:

• JAMB 1979

The reaction between hydrogen and iodine may be represented by the equation H₂(g)+ I₂(g) → 2HI(g), and is exothermic. Therefore

A. An increase in temperature favours the forword reaction
B. An increase in pressure favours the backward reaction
C. Both pressure and temperature muct be increased to favour the forward reaction
D. A decrease in temperature will favour the forward reaction
E. A decrease in pressure and an increase in temperature will favour the forward reaction

Question 7:

• JAMB 1979

The reaction 3C(s) + 2Fe₂O₃(s) = 4Fe(s) + 3CO₂(g): \(\Delta\)H =46.0 kJ is

A. Isothermic
B. Adiabatic
C. Isobaric
D. Endothermic
E. Exothermic

Question 8:

• JAMB 1982

0.16g of methane when burnt raises the temperature of 100g of water by 40°C. What is the of combustion of methane when if the heat capacity of water is 4.2 Jg^-1°C^-1?
(CH₄ = 16)

A. 1,160 kJ mol^-1
B. 1,180 kJ mol^-1
C. 1,560 kJ mol^-1
D. 1,600kJ mol^-1
E. 1,680 kJ mol^-1

Question 9:

• JAMB 1982

Which of the following processes NOT lead to a chemical change?

A. Strirring iron in sulphur (IV) acid
B. Stirring sodium carbonate in water
C. Stirring glucose in concentrated sulphur (IV) acid
D. Mixing sulphur (IV) acid with potassium carbonate
E. Titrating an acid against base

Question 10:

• JAMB 1983

The colour imparted to a flame by calcuium ion is

A. Green
B. Blue
C. Brick-red
D. Yellow
E. Lilac