Post Utme Chemistry Past Questions and Answers

Question 371:

What amount of copperwill be deposited if a current of 10 A was passed through a solution of copper
(ii) salt for 965 seconds? (IF=96500 C)

A. \(0.005\) mole
B. \(0.025\) mole
C. \(0.05\) mole
D. \(1.00\) mole

Question 372:

Consider the reaction represented by the following equation:
\(\mathrm{CaCl}_{2+0}+\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{2} \quad \mathrm{CaC}_{2} \mathrm{O}_{\text {ae }}+2 \mathrm{HCl}_{2 \text { an }}\)
which of the following would dissolve the precipitate of \(\mathrm{CaC}_{2} \mathrm{O}_{2}\) formed?

A. Stirring the mixture vigorously
B. Adding more calcium chloride solution
C. Increasing the concentration of the ethanedioic acid \(\quad\)
D. Adding concentrated hydrochloric acid.

Question 373:

What volume of distilled water should be added to \(400 \mathrm{~cm}^{-3}\) of \(2.0\) mole dm \({ }^{-3} \mathrm{H}_{2} \mathrm{SO}_{4}\), to obtain \(0.20\) mole dm \({ }^{3}\) of solution?

A. \(600 \mathrm{~cm}^{2}\)
B. \(800 \mathrm{~cm}^{2}\)
C. \(1,000 \mathrm{~cm}^{1}\)
D. \(3,600 \mathrm{~cm}^{3}\)

Question 374:

What volume of propane is left unreacted when \(20 \mathrm{~cm}^{3}\) of oxygen and \(20 \mathrm{~cm}^{3}\) of propane react according to the following equation?
\(\mathrm{C}_{1} \mathrm{H}_{3}+5 \mathrm{O}_{\text {ue }} \quad 3 \mathrm{CO}_{4 \mathrm{we}}+4 \mathrm{H}_{2} \mathrm{O} \)

A. \(16 \mathrm{~cm}^{\prime} \)
B. \(5 \mathrm{~cm}^{2}\)
C. \(14 \mathrm{~cm}^{2} \)
D. \(15 \mathrm{~cm}^{2}\)

Question 375:

The component of air that is removed when air is bubbled into alkaline pyrogallol solution is ____________

A. Carbon (IV) oxide
B. Oxvgen
C. Water vapou
D. Nitrogen