Post Utme Chemistry Past Questions and Answers

Question 231:

\(2 \mathrm{SO}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})} \leftrightharpoons 2 \mathrm{SO}_{3(\mathrm{~g})} \Delta \mathrm{H}=-\) 395.7 \(\mathrm{Kjmol}^{-1}\)

The reaction above, the concentration of \(\mathrm{SO}_{3(\mathrm{~g})}\) can be increased by ____________

A. Decreasing the pressure
B. Decreasing the temperature
C. Increasing the temperature
D. The addition of catalyst

Question 232:

Which of the following compounds is a normal salt?

A. \(\mathrm{Na}_{2} \mathrm{CO}_{3}\)
B. \(\mathrm{NaH}_{\mathrm{SO}}^{4}\)
C. \(\mathrm{NaHCO}_{3}\)
D. \(\mathrm{NaHS}\)

Question 233:

Which of the following ions can be used as an oxidizing agent?

A. \(F\) -
B. \(\mathrm{Fe}^{3+}\)
C. \(\mathrm{Au}^{3+}\)
D. \(\mathrm{Ca}^{2+}\)

Question 234:

\(\mathrm{CO}_{(\mathrm{g})}+\mathrm{H}_{2} \mathrm{O}_{(\mathrm{g})}
ightarrow \mathrm{CO}_{2(\mathrm{~g})}+\mathrm{H}_{2(\mathrm{~g})}\) Calculate the standard heat change of the reaction above if the standard enthalpies of formation of \(\mathrm{CO}_{2(g)}, \mathrm{H}_{2} \mathrm{O}_{(g)}\) and \(\mathrm{CO}_{(\mathrm{g})}\) in \(\mathrm{KJmol}^{-1}\) are \(-394,-242\) and \(-110\) respectively.

A. \(+262 \mathrm{KJ} \mathrm{mol}^{-1}\)
B. \(-262 \mathrm{KJ} \mathrm{mol} \mathrm{m}^{-1}\)
C. \(+42 \mathrm{KJ} \mathrm{mol}^{-1}\)
D. \(-42 \mathrm{KJ} \mathrm{} \mathrm{mol}^{-1}\)

Question 235:

\(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CL}+\mathrm{KCN}
ightarrow \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CN}\)
\(+\mathrm{KCl}\)
In the reaction above. the cyanide is

A. Nucleophilic
B. Electrophilic
C. Hydrophilic
D. Hydrophobic