Post Utme University of Nigeria Chemistry Past Questions and Answers

Question 1:

Which of the following ions is isoelectronic with neon? [3Li, 9F, \(10 \mathrm{Ne}, 17 \mathrm{Cl}, 19 \mathrm{~K}]\)

A. \(\mathrm{Cl}-\)
B. F-
C. \(\mathrm{K}+\)
D. Li+

Question 2:

Which of the following gases is employed as an anaesthesia?

A. \(\mathrm{NH}_{3}\)
B. NO
C. \(\mathrm{N}_{2} \mathrm{O}\)
D. \(\mathrm{NO}_{2}\)

Question 3:

Aluminium is extracted commercially from its ore by ____________

A. Heating aluminium oxide with coke in a furnace
B. The electrolysis of fused aluminium oxide in cryolite
C. Treating cryolite with sodium hydroxide solution under pressure
D. Heating sodium aluminium silicate to a high temperature

Question 4:

The atomic number of Caesium is 55 and its atomic mass is ____________

A. 78 protons and 55 electrons
B. 55 protons and 78 neutrons
C. 55 neutrons and 78 electrons
D. 78 neutrons and 55 neutrons

Question 5:

The solubility in moles per \(\mathrm{dm}^{3}\) of \(20 \mathrm{~g}\) of \(\mathrm{CuSO}_{4}\) dissolved in \(100 \mathrm{~g}\) of water at \(180^{\circ} \mathrm{C}\) is ____________

A. \(0.13\)
B. \(0.25\)
C. \(1.25\)
D. \(2.00\)