Jamb Chemistry Past Questions and Answers

Question 1476:

• JAMB 2008

NH_3(g) + HCl_(s) → NH₄Cl_(s)
The entropy change in the system above is

A. Positive
B. Zero
C. Negative
D. Indeterminate

Question 1477:

• JAMB 2008

Which of the following reaction is endothermic?

A. C_(s) + O_2(g) → CO_2(g)
B. CaO_(s) + H₂O_(l) → Ca(OH)_2(s)
C. C_(s) + H₂O_(g) → CO_(g) + H_2(g)
D. HCl_(aq) + NaOH_(aq) → NaCl_(aq) + H₂O_(l)

Question 1478:

• JAMB 2008

A catalyst speeds up the rate of chemical reaction by

A. Taking part in the reaction
B. Increasing the activation energy of the reaction
C. Lowering the activation energy of the reaction
D. Increasing the heat content

Question 1479:

• JAMB 2008

The rate of a reaction usually decrease in the concentration of reactants because

A. Kinetic energy decrease
B. Temperature increase
C. Speed increases
D. Reactants collision decrease

Question 1480:

• JAMB 2008

The substance that is used in the steel industry for the removal of carbon, sulphur and phosphorus impurities from pig iron is

A. Oxygen
B. Chlorine
C. Nitrogen
D. Hydrogen