Post Utme University of Port Harcourt Chemistry Past Questions and Answers

Question 16:

A certain volume of a gas at \(298 \mathrm{~K}\) is heated such that its volume and pressure are now four times the original values. What is the new temperature?

A. \(18.6 \mathrm{~K}\)
B. \(100 \mathrm{~K}\)
C. \(298.0 \mathrm{~K}\)
D. \(1192.0 \mathrm{~K}\)
E. \(4768.0 \mathrm{~K}\)

Question 17:

The mass of silver deposited when a current of \(10 \mathrm{~A}\) is passed through a solution of silver salt for 4830s?

\(\left[\mathrm{Ag}=106 \mathrm{~g}, \mathrm{~F}=96500 \mathrm{Cmol}^{-1} \rsight]\)

A. \(108.0 \mathrm{~g}\)
B. \(54.0 \mathrm{~g}\)
C. \(27.0 \mathrm{~g}\)
D. \(13.6 \mathrm{~g}\)

Question 18:

\(2 \mathrm{CO}+\mathrm{O}_{2} \rightarrow 2 \mathrm{CO}_{2(\mathrm{~g})}\). Given that \(\Delta \mathrm{H}[\mathrm{CO}]\) is \(-110.4 \mathrm{kJmol}\) and \(\mathrm{H}\left[\mathrm{CO}_{2} \right]\) is \(-393.0 \mathrm{kJmol}^{-1}\) the energy change of the reaction above is?

A. \(-565.21 \mathrm{~kJ}\)
B. \(-282.6 \mathrm{~kJ}\)
C. \(+282.6 \mathrm{~kJ}\)
D. \(+565.2 \mathrm{k}]\)

Question 19:

How many moles of limestone will he required to produce \(5.6 \mathrm{~g}\) of \(\mathrm{CaO}\) ?

A. \(0.20 \mathrm{~mol}\)
B. \(0.10 \mathrm{~mol}\)
C. \(1.12 \mathrm{~mol}\)
D. \(0.56 \mathrm{~mol}\)

Question 20:

One mole of propane is mixed with five moles of oxygen. The mixture is ignited and the propane bums completely. What is the volume of the product at s.t.p? [M.V.G \(=22.4 \mathrm{dm} 3\) ]

A. \(112.0 \mathrm{dm}^{3}\)
B. \(67.2 \mathrm{dm}^{3}\)
C. \(56.0 \mathrm{dm}^{3}\)
D. \(44.8 \mathrm{dm}^{3}\)