Post Utme Chemistry Past Questions and Answers

Question 1141:

What happens to the conductivity of an electrolyte as its concentration reduces?

A. Increases
B. Decreases
C. Is unaffected
D. Becomes resistivity

Question 1142:

If the cost of electricity required to deposit \(1 g\) of aluminum is \(\# 4.00\), how much would it cost to deposit \(24 g\) of copper' \([ A ]=27, Cu =64]\)

A. #27.02
B. #37.02
C. #47.02
D. #57.02

Question 1143:

The ov erall reaction in an electrochemical cell is \(Mg _{(51} \cdot Cu _{(\text {(a) })}^{2+} \rightarrow Mg _{( aq )}^{2+}+ Cu _{( s )}\) *
What is the symbolic representation of the cell?

A. \(Mg _{k}, Mg _{\text {(aq) }}^{2+} \| Cu _{(a-1)}^{2 *} / Cu _{(3)}\)
B. \(M _{ g _{n i 1}} / Mg _{(i)}^{2+} \| Cu _{( s )}^{2+} / Cu _{(\text {aq })}\)
C. \(Cu _{(\text {aq }}^{2+} / Cu _{(s)} \| Mg _{(s)} / Mg _{(\text {(a) }}^{2+}\)
D. \(Cu _{( s )} / Cu _{( sq )}^{2+} \| Mg _{( aq )}^{2+} / Mg _{(s)}\)

Question 1144:

Which of the following metals can be used as sacrificial cathode for preventing corrosion of a length of iron pipe?

A. Ag
B. Cu
C. Mg
D. Mn

Question 1145:

A particle that contains 8 protons, 9 neutrons and 7 electrons could be written as ____________

A. \({ }_{8}^{16} O\)
B. \({ }_{8}^{17} O ^{-}\)
C. \({ }_{9}^{17} O ^{-}\)
D. \({ }_{8}^{17} O\)