Post Utme Chemistry Past Questions and Answers

Question 1001:

What is the chemical formula of the compound containing: \(6.02 \times 10^{23}\) atoms of hydrogen, \(35 g\) of chlorine, and 4 moles of oxygen atoms?

A. \(HCl _{4} O\)
B. \(HClO\)
C. \(HClO _{4}\)
D. \(HCl _{2} O _{4}\)

Question 1002:

\(200 cm ^{3}\) of hydrogen were collected over water at \(30^{\circ} C\) and \(740 mm\) of \(Hg\). Calculate the volume of the gas at s.t.p. If the vapour pressure of water at the temperature of the experiment is \(14 mm\) of \(Hg .

A. \(168 .25 cm ^{3}\)
B. \(176.40\) \(cm ^{3}\)
C. \(185.46 cm ^{3}\)
D. \(172.14 cm ^{3}\)

Question 1003:

A given mass of gas occupies a certain volume at \(300 K\) At what temperature will its volume be doubled?

A. \(400 K\)
B. \(480 K\)
C. \(550 K\)
D. \(600 K\)

Question 1004:

The basic assumption in the kinetic theory of gas that: "forces of attraction and repulsion between gaseous molecules are negligible" implies that ____________

A. Molecules will continue their motion indefinitely
B. Gases will occupy any available space
C. Gases can be compressed
D. None of the above

Question 1005:

Which of the following is true of a sample of hydrogen gas whose mass is \(4.00 g\) under a pressure of \(2 atm\) and a temperature of \(27^{\circ} C\) ? \(\left( H =1, R =0.082\right.\) lit atm. \(Mol ^{-1}\) \(\operatorname{deg}-1\) )

A. Its volume is \(24.6\) litres
B. It contains \(6.02 \times 10^{23}\) molecules
C. It exists as atoms because of temperature
D. None of the above