Post Utme Chemistry Past Questions and Answers

Question 71:

A ketone reacts with hydroxylamine to give ____________

A. A hydrazone
B. An alkanonitrile
C. A nitroso compound
D. An oxime

Question 72:

Alkanoic acids are weak acids and ionises in solution to give ____________

A. \(\mathrm{R}^{+}+\mathrm{COOH}\)
B. \(\mathrm{RCOO}^{-}+\mathrm{H}^{+}\)
C. \(\mathrm{RCOO}^{+}+\mathrm{H}^{-}\)
D. \(\mathrm{RCO}^{+}+\mathrm{OH}^{-}\)

Question 73:

An excess of ethanol heated with concentrated \(\mathrm{H}_{2} \mathrm{SO}_{4}\) at a temperature of \(180^{\circ} \mathrm{C}\) is dehydrated to give mostly ____________

A. Ethane
B. Ethene
C. Ethanol
D. Ethoxyethane

Question 74:

Butene can be distinguished from benzene by reaction with ____________

A. Hydrochloric acid
B. Bromine water
C. Potassium sulphate
D. Sodium hydroxide

Question 75:

Detergent is more efficient than soap in cleansing clothes and dishes because of the following reasons except that ____________

A. The corresponding \(\mathrm{Ca}\) and \(\mathrm{Mg}\) compound formed is soluble in \(\mathrm{H}_{2} \mathrm{O}\)
B. Detergents are not affected by hardness of water
C. It cleans better than soap
D. It is less expensive