Electrode Potentials

• -0.41V

• -0.27 V

• +0.27 V

• +0.41 V

The salt bridge is best prepared by soaking filter paper in

• 1 mol dm^-3 solution of potassium bromide

• 1 mol dm^-3 solution of potassium chloride

• saturated solution of potassium nitrate

• saturated solution of potassium iodide

The relevant standard electrode potentials for this cell are shown below.

Cr3+(aq) + 3e- ⇌ Cr(s) E= − 0.74 V

Ag+(aq) + e− ⇌ Ag(s) E = + 0.80 V

Calculate the emf of the cell shown in the diagram.

• +1.54 V

• -1.54 V

• + 0.06 V

• - 0.06 V

The mass of 1 mol of chromium(III) sulfate (Cr₂(SO₄)₃) is 392 g. Hence, for the cell in the diagram to measure the standard electrode potential, 1 dm³ of the chromium(III) sulfate solution used must contain

• 104g of chromium(III) sulfate

• 196g of chromium(III) sulfate

• 392g of chromium(III) sulfate

• 784g of chromium(III) sulfate

Which species will oxidise Fe²⁺(aq) to Fe³⁺(aq)?

• Br_{2 (aq)}

• Cl^-_(aq)

• I_{2 (aq)}

• Mn²⁺_(aq)

Calculate the emf for the reaction between MnO₄^– ions and Br^– ions in acidic solution.

• -0.42 V

• +0.42 V

• +2.60 V

• -2.60 V

The electrode system based on the half-equation below has the standard electrode potential +1.51 V.

MnO₄⁻_(aq) + 8H⁺_(aq) + 5e⁻ ⇌ Mn²⁺_(aq) + 4H₂O_(l)

Which of the following statements about this electrode system is correct?

• Changing the concentration of Mn²⁺(aq) would cause a change in the electrode potential.

• Mn²⁺(aq) is acting as an oxidizing agent.

• The electrode used is made of manganese.

• When connected to a standard hydrogen electrode, the resulting cell voltage would be +0.51 V.

The standard electrode potentials of two half reactions are shown.

Which of the following processes is thermodynamically favourable? The reaction of

• Co²⁺ with Cl₂ to form Cl⁻

• Co²⁺ with Cl⁻ to form Cl₂

• Co³⁺ with Cl₂ to form Cl⁻

• Co³⁺ with Cl⁻ to form Cl₂

At 298 K, the emf of this cell was +0.40 V.

The electrode potential of the copper metal / copper(II) ion electrode is +0.34 V.

What is the electrode potential of this silver metal / silver(I) ion electrode?

• -0.74 V

• -0.06 V

• + 0.74 V

• + 0.06 V

Which of the statements about a standard hydrogen electrode, for which E = 0 V, is correct?

• A suitable solution for use in the electrode is hydrochloric acid with a concentration of 0.1 mol dm⁻³.

• The pressure of the hydrogen has no effect on the value of E

• The metal used in the electrode is platinum.

• The temperature is 273 K.