Post Utme Chemistry Past Questions and Answers

Question 141:

\(3 \mathrm{~g}\) of a mixture of \(\mathrm{CaO}\) and \(\mathrm{CaCO}_{3}\) was heated to a constant mass. If \(0.44 \mathrm{~g}\) of \(\mathrm{CO}_{2}\) was liberated, calculate the percentage of \(\mathrm{CaO}\) in the mixture.

A. \(33.3 \%\)
B. \(50 \%\)
C. \(66.67 \%\)
D. 25%

Question 142:

an alkanoic acid has a molecular mass of 88. Its molecular formula is ____________

A. \(\mathrm{C}_{4} \mathrm{H}_{9} \mathrm{COOH}\)
B. \(\mathrm{C}_{5} \mathrm{H}_{11} \mathrm{COOH}\)
C. \(\mathrm{C}_{3} \mathrm{H}_{5} \mathrm{COOH}\)
D. \(\mathrm{C}_{3} \mathrm{H}_{7} \mathrm{COOH}\)

Question 143:

If the rate of diffusion of Oxygen is taken as \(1 \mathrm{cms}^{-1}\), what will be the rate of diffusion of methane whose molecular mass is \(16 ?\)

A. \(2.0\)
B. \(1.8\)
C. \(1.4\)
D. \(1.0\)

Question 144:

An increase in temperature causes an increase in the pressure of a gas in a fixed volume due to an increase in the ____________

A. Number of molecules of the gas
B. Density of the gas molecules
C. Number of collisions between the gas molecules
D. Number of collisions between the gas molecules and the walls of the container

Question 145:

In electrolysis, the chemical reaction which takes place at the anode is ____________

A. Dissociation
B. Hydrolysis
C. Oxidation
D. Reduction