Jamb Chemistry Past Questions and Answers

Question 411:

• JAMB 1985

A man suspected of being drunk is made to pass his breath into acidified potassium dichlormate solution. If his breath carries a significant level of ethanol, the final colour of the solution is?

A. Pink
B. Purple
C. Orange
D. Blue-black
E. Green

Question 412:

• JAMB 1985

When pollen grains are suspended in water and viewed through a microscope, they appear to be in a state of constant but erratic motion. This is due to?

A. Convection currents
B. Small changes
C. Small changes in temperature
D. A chemical reaction between the pollen grain and water
E. The bombardment of the pollen grains by molecules of water

Question 413:

• JAMB 1985

The energy change (ΔH) for the reaction CO(g) + (1)/(2)O_2(g) → is?
(ΔHi(CO) = -110.4 kJ mol^-) (ΔHi(CO₂) = -393 kJ mol^-)

A. -503.7 kJ
B. +503.7kJ
C. -282.9 kJ
D. +282.9 kJ
E. +393.3 kJ

Question 414:

• JAMB 1985

Tetraoxosulphate (IV) ions are finally tested using?

A. Acidified silver nitrate
B. Acidified barium chloride
C. Ime-water
D. Dilute hydrochloric acid
E. Acidified lead nitrate

Question 415:

• JAMB 1985

An organic compound decolourized acidified KMnO₄ solution but failed to react with ammoniacal silver nitrate solution. The organic compound is likely to be?

A. A carbonxylic acid
B. An alkane
C. An alkene
D. An alkyne
E. An akanone