Post Utme Chemistry Past Questions and Answers

Question 721:

An organic compound decolourized acidified \(\mathrm{KMnO}_{4}\) solution but failed to react with ammoniacal \(\mathrm{AgNO}_{3}\) solution. The organic compound is likely to ____________

A. A carboxylic acid
B. Alkane
C. Alkene
D. Alkyne

Question 722:

A certain volume of a gas at \(298 \mathrm{~K}\) is heated such that its volume and pressure are now four times the original values. What is the new temperature?

A. \(18.6 \mathrm{~K}\)
B. \(100.0 \mathrm{~K}\)
C. \(298.0 \mathrm{~K}\)
D. \(1192.0 \mathrm{~K}\)
E. \(4768.0 \mathrm{~K}\)

Question 723:

The boiling points of water, ethanol, toluene and button-2-ol are \(373.0 \mathrm{~K}, 351.3 \mathrm{~K}\), \(383.6 \mathrm{~K}\) and \(372.5 \mathrm{~K}\) respectively. Which liquid has the highest vapour pressure at 323.0K?

A. Water
B. Toluene
C. Ethanol
D. Dutan-2-ol
E. None

Question 724:

The function of sulphur during the vulcanization of rubber is to ____________

A. Act as catalyst for the polymerization of rubber molecules
B. Convert rubber from thermosetting to thermoplastic polymer
C. From chains which bind rubber molecules together
D. Break down rubber polymer molecule
E. Shorten the chain length of rubber polymer

Question 725:

Complete hydrogenation of ethyne yields

A. Benzene
B. Methane
C. Ethane
D. Ethene
E. Propane