Welcome to the Quiz!
This quiz contains 8 questions from a mix of 1 subtopics.
A reaction will take place if the redox system of the species being oxidised has a more E⦵ value than the redox system of the species being reduced.
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Do feasible redox reactions have E⦵cell values that are positive or negative?
negative
positive
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Which reaction between chromium and lead is feasible?
Cr3+(aq) + e- ⇌ Cr2+(aq) E⦵ = -0.41 V
Pb2+(aq) + 2e- ⇌ Pb(s) E⦵ = -0.76 V
2Cr2+ + Pb2+ ➔ 2Cr3+ + Pb
2Cr3+ + Pb ➔ 2Cr2+ + Pb2+
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Which redox reaction is the most feasible?
Cr3+(aq) + 3e- ⇌ Cr(s) E⦵ = -0.77 V
Cu2+(aq) + 2e- ⇌ Cu(s) E⦵ = +0.34 V
Ag+(aq) + e- ⇌ Ag(s) E⦵ = +0.80 V
2Ag+ + Cu ➔ 2Ag + Cu2+
3Ag+ + Cr ➔ 3Ag + Cr3+
3Cu2+ + 2Cr ➔ 3Cu + 2Cr3+
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Calculate the value of E⦵cell for the reaction of Mg with Zn2+ ions:
Mg2+(aq) + 2e- ⇌ Mg(s) E⦵ = -2.38 V
Zn2+(aq) + 2e- ⇌ Zn(s) E⦵ = -0.76 V
V
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Give two limitations of using standard electrode potentials to predict the feasibility of redox reactions.
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How would Cu/Cu2+ elecrode potential (E) change if the concentration of Cu2+ ions was lower than 1 mol dm-3?
Cu2+(aq) + 2e- ⇌ Cu(s) E⦵ = +0.34 V
E would become more positive
E would become less positive
E would remain unchanged
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How would Fe2+/Fe3+ elecrode potential, E, change if the concentrations of Fe2+ and Fe3+ ions were changed by the same amount?
Fe3+(aq) + e- ⇌ Fe2+(aq) E⦵ = +0.77 V
E would become more positive
E would become less positive
E would remain unchanged
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