Welcome to the Quiz!
This quiz contains 7 questions from a mix of 1 subtopics.
What principle underpins modern cells and batteries?
the two electrodes have the same electrode potential
the cell reaction cannot be revered
the two electrodes have different electrode potentials
the cell reaction can be revered
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How long can fuel cells operate with a constant supply of oxygen and fuel?
for a short period of time until they need to be recharged
continously
for a long period of time until they need to be recharged
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Which type of cell can have its cell reaction reversed by applying an external current?
non-rechargeable cell
fuel cell
rechargeable cell
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In the non-rechargeable Zn/MnO2 cell, which species is reduced and which species is oxidised during cell operation?
ZnO(s) + H2O(l) + 2e- ⇌ Zn(s) + 2OH-(aq) E⦵ = -1.28 V
2MnO2(s) + H2O(l) + 2e- ⇌ Mn2O3(s) + 2OH-(aq) E⦵ = +0.15 V
MnO2 is reduced and Zn is oxidised
Mn2O3 is reduced and ZnO is oxidised
Mn2O3 is oxidised and ZnO is reduced
MnO2 is oxidised and Zn is reduced
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A lithium ion battery has a voltage of +4.20 V when fully charged
What is the E⦵ value of the CoO2 electrode?
Li+ + e- ⇌ Li E⦵ = -3.04 V.
V
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Which half-equation represents the oxidation reaction occuring in an alkaline hydrogen-oxygen fuel cell?
O2(g) + 4H+(aq) + 4e- ➔ 2H2O(l)
H2(g) ➔ 2H+(aq) + 2e-
O2(g) + 2H2O(l) + 4e- ➔ 4OH-(aq)
H2(g) + 2OH-(aq) ➔ 2H2O(l) + 2e-
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Which half-equation represents the reduction reaction occuring in an alkaline hydrogen-oxygen fuel cell?
O2(g) + 2H2O(l) + 4e- ➔ 4OH-(aq)
H2(g) ➔ 2H+(aq) + 2e-
H2(g) + 2OH-(aq) ➔ 2H2O(l) + 2e-
O2(g) + 4H+(aq) + 4e- ➔ 2H2O(l)
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