Post Utme Chemistry Past Questions and Answers

Question 96:

Consider the reaction represented by \(\mathrm{xPb}(\mathrm{NO})_{2} \rightarrow 2 \mathrm{PbO}+\mathrm{yNO}_{2}+\mathrm{zO}_{2}\) What are the values of \(x, y\) and \(z\) respectively?

A. \(2,6,3\)
B. \(1,4,2\)
C. \(2,4,1\)
D. \(2,4,2\)

Question 97:

\(20 \mathrm{~cm}^{3}\) of \(\mathrm{H}_{2}\) mixed and separated with \(100 \mathrm{~cm}^{3}\) of air containing \(21 \% \mathrm{O}_{2}\).
Calculate the volume of the residual gases at \(110^{\circ} \mathrm{C}\).

A. \(31 \mathrm{~cm}^{3}\)
B. \(11 \mathrm{~cm}^{3}\)
C. \(90 \mathrm{~cm}^{3}\)
D. \(110 \mathrm{~cm}^{3}\)

Question 98:

What is responsible for metallic bonding?

A. Sharing of electrons between the metal atoms
B. Attraction between the atomic nuclei and the cloud of electrons
C. Transfer of electrons from one atom to another
D. Attraction between positive and negative ions

Question 99:

\(25 \mathrm{~cm}^{3}\) of \(1.5 \mathrm{M}\) solution of \(\mathrm{NaCl}\) are added to \(50 \mathrm{~cm}^{3}\) of \(3 \mathrm{M}\) \(\mathrm{NaCl}\). The molar concentration of the resulting solution is ____________

A. \(2.5 \mathrm{M}\)
B. \(3 \mathrm{M}\)
C. \(2.25 \mathrm{M}\)
D. \(4.5 \mathrm{M}\)

Question 100:

A solution of salt formed from \(\mathrm{HCl}\) and \(\mathrm{NH} 3\) solutions is ____________

A. Acidic
B. Basic
C. Complex
D. Neutral