Post Utme Chemistry Past Questions and Answers

Question 241:

In an equilibrium reaction, which of the following conditions indicates that maximum yield of product will be obtained?

A. Equilibrium constant is very large
B. \(\Delta \mathrm{H}-\mathrm{T} \Delta \mathrm{S}=0\)
C. \(\Delta \mathrm{H}>\mathrm{T} \Delta \mathrm{S}\)
D. Equilibrium constant is less than zero

Question 242:

\(2 \mathrm{C}_{2} \mathrm{H}_{2(\mathrm{~g})}+5 \mathrm{O}_{2(\mathrm{~g})}
ightarrow 4 \mathrm{CO}_{2(\mathrm{~g})}+\) \(2 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})}\)

In the reaction above, the mass or carbon(IV) oxide produced by burning \(78 \mathrm{~g}\) of ethyne is ____________

A. \(264 \mathrm{~g}\)
B. \(352 \mathrm{~g}\)
C. \(39 \mathrm{~g}\)
D. \(156 \mathrm{~g}\)

Question 243:

\(\mathrm{Cu}(a q)^{2+}+4 \mathrm{NH}_{3(g)} \rightleftharpoons\) \(\left[\mathrm{Cu}\left(\mathrm{NH}_{3} \right)_{4} \right](a q)^{2+}\)

In the reaction above, what is the effect of precipitating \(C u(a q)^{2+}\) as \(\mathrm{CuS}_{(\mathrm{s})}\)

A. \(\mathrm{NH}_{3(9)}\) concentration will decrease
B. More \(\mathrm{NH}_{3(9)}\) will be generated
C The equilibrium will shift to the right
C. There will be no effect

Question 244:

Which of the following gases can be used to demonstrate the experiment?

A. Hydrogen chloride
B. Hydrogen sulphide
C. Nitrogen(II) oxide
D. Dinitrogen(I) oxide

Question 245:

The colour of the fountain water is ____________

A. Orange
B. Blue
C. Red
D. Yellow