M5S17 – Electrode Potentials 2

When gases are involved in half-cells, what pressure of gas is required for the determination of a standard cell potential, E^ϴcell/V?

What is the value of E^ϴcell/V observed for a cell constructed from the following half-cells?

Fe³⁺_(aq) + e^- <=> Fe²⁺_(aq) E^ϴ/V = +0.77

MnO₄^-_(aq) + 8H⁺_(aq) + 5e^- <=> Mn²⁺_(aq) + 4H₂O_(aq) E^ϴ/V = +1.51

Consider a cell constructed from the following half-cells:

Fe³⁺_(aq) + e^- <=> Fe²⁺_(aq) E^ϴ/V = +0.77

MnO₄^-_(aq) + 8H⁺_(aq) + 5e^- <=> Mn²⁺_(aq) + 4H₂O_(aq) E^ϴ/V = +1.51

If the solution of Fe²⁺_(aq) was 2.00 mol dm^-3, would you expect to see a greater or smaller value of E^ϴcell/V than you would if the cell was set-up under standard conditions?

What is the value of E^ϴcell/V observed for a cell constructed from the following half-cells? These half-cells are those involved in Hydrogen Fuel Cells when operated in acidic conditions?

H⁺_(aq) + e^-<=> ½H_2(g) (acidic conditions) E^ϴ/V = 0.00

O_2(g)+ 4H⁺_(aq) + 4e^-<=>2H₂O_(g) (acidic conditions) E^ϴ/V = +1.23

What is the value of E^ϴcell/V observed for a cell constructed from the following half-cells. (These are the half-cells that are put together in a car battery (6 cells in series)?

PbSO_4(s) + 2e^- <=> Pb_(s) + SO₄^2-_(aq) E^ϴ/V = -0.36

PbO_2(s) + SO₄^2-_(aq)+4H_(aq) + 2e^- <=> PbSO_4(s) + 2H₂O(l) E^ϴ/V = +1.69

High resistance voltmeters are required for accurate values of E^ϴcell/V to be measured.

What statement best describes the reasoning behind the use of a high resistance voltmeter?

For this question, look at the resource, ‘A Selection of Standard Electrode Potentials’ (‘A Selection of Standard Electrode Potentials’can be found in TOOLS>Data Sheets)

Which chemical species is the most powerful oxidising agent?

For this question, look at the resource, ‘A Selection of Standard Electrode Potentials’ (‘A Selection of Standard Electrode Potentials’can be found in TOOLS>Data Sheets)

Under standard conditions, can Mg²⁺_(aq) be reduced to Mg_(s) by Ca_(s)?

For this question, look at the resource, ‘A Selection of Standard Electrode Potentials’ (‘A Selection of Standard Electrode Potentials’can be found in TOOLS>Data Sheets)

Under standard conditions, can Br_2(aq) oxidise Cr³⁺_(aq) to dichromate(VI)?

For this question, look at the resource, ‘A Selection of Standard Electrode Potentials’ (‘A Selection of Standard Electrode Potentials’can be found in TOOLS>Data Sheets)

When nitric(V)acid is added to a purple solution of V²⁺_(aq) ions and the mixture allowed to stand for a few minutes, what colour will be observed in the solution?