Post Utme Chemistry Past Questions and Answers

Question 111:

The partial pressure of \(N_{2}\) in a container at \(50^{\circ} \mathrm{C}\) in which there are \(0.30\) mole of \(\mathrm{N}_{2}\) and \(1.2\) mole of \(\mathrm{CO}_{2}\) at a pressure of \(2.00 \mathrm{~atm}\) is?

A. \(0.6\) atm
B. \(0.5 \mathrm{~atm}\)
C. \(0.4 \mathrm{~atm}\)
D. \(1.6 \mathrm{~atm}\)

Question 112:

The major reason why chemical reaction occurs among elements is that they have the tendency to ____________

A. Attain the nearest noble gas structure
B. Become a metal
C. Become a non-metal
D. Become a noble element

Question 113:

Given that the pH of a solution of \(\mathrm{KOH}\) is 12 , what is the concentration oh he OH-ions?

A. \(0.01 \mathrm{~mol} / \mathrm{dm}^{3}\)
B. \(1 \times 10^{-12} \mathrm{~mol} / \mathrm{dm}^{3}\)
C. \(1 \times 10^{-14} \mathrm{~mol} / \mathrm{dm}^{3}\)
D. \(1 \times 10^{-7} \mathrm{~mol} / \mathrm{dm}^{3}\)

Question 114:

Which of the following salt has a pH less than 7?

A. \(\mathrm{NaHCO}_{3}\)
B. \(\mathrm{NH}_{4} \mathrm{Cl}\)
C. \(\mathrm{Na}_{2} \mathrm{SO}_{4}\)
D. \(\mathrm{NaCl}\)

Question 115:

In which of the following reactions. does hydrogen peroxide act as a reducing agent?

A. \(\mathrm{PbO}_{2}+2 \mathrm{HNO}_{3}+\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow\) \(\mathrm{Pb}\left(\mathrm{NO}_{2} \right)_{3}+2 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}\)
B. \(\mathrm{H}_{2} \mathrm{~S}-\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow \mathrm{S}+2 \mathrm{H}_{2} \mathrm{O}\)
C. \(\mathrm{PbSO}_{2}+\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow \mathrm{PbSO}_{4}+\mathrm{H}_{2} \mathrm{O}\)
D. \(2 \mathrm{I}+2 \mathrm{H}+\mathrm{H}, \mathrm{O}, \rightarrow \mathrm{I},+2 \mathrm{H}, \mathrm{O}\)