Post Utme Chemistry Past Questions and Answers

Question 131:

Which of the following is an acid salt?

A. \(\left(\mathrm{NH}_{4}
ight)_{2} \mathrm{CO}_{3}\)
B. CHCOONa
C. \(\mathrm{KHSO}_{4}\)
D. \(\mathrm{MgSO}_{4} \cdot 7 \mathrm{H}_{2} \mathrm{O}\)

Question 132:

\(\mathrm{CrO}_{7}^{2-}+14 \mathrm{H}^{+}+6 \mathrm{I} \rightarrow 2 \mathrm{Cr}^{3+}+\) \(3 \mathrm{I}_{2}+7 \mathrm{H}_{2} \mathrm{O}\) 12. The solubility of a salt of molar mass \(100 \mathrm{~g}\) at \(20^{\circ} \mathrm{C}\) is \(0.34 \mathrm{~mol} / \mathrm{dm}^{3}\). If \(3.4 \mathrm{~g}\) of that salt dissolved completely in \(250 \mathrm{~cm}^{3}\) of water at that temperature, the resulting solution is ____________

A. A suspension
B. Saturated
C. Unsaturated
D. Supersaturated

Question 133:

During the electrolysis of \(\mathrm{CuSO}_{4}\), solution using Platinum electrodes, which of the following occurs?

A. Acidity increases at the cathode
B. Oxygen is liberated at the cathode
C. \(\mathrm{pH}\) decreases at the cathode
D. \(\mathrm{pH}\) of solution decreases

Question 134:

Which of the following ions is a pollution in drinking water even in trace quantities?

A. \(\mathrm{Ca}^{2+}\)
B. \(\mathrm{Pb}^{2+}\)
C. \(\mathrm{Mg}^{2+}\)
D. \(\mathrm{Fe}^{2+}\)

Question 135:

The solubility of a salt of molar mass \(100 \mathrm{~g}\) at \(20^{\circ} \mathrm{C}\) is \(0.34 \mathrm{~mol} / \mathrm{dm}^{3}\). If \(3.4 \mathrm{~g}\) of that salt dissolved completely in \(250 \mathrm{~cm}^{3}\) of water at that temperature, the resulting solution is ____________

A. A suspension
B. Saturated
C. Unsaturated
D. Supersaturated