Electrochemistry

How would you determine the standard electrode potential of the system Mg²⁺ | Mg?

Can you store copper sulphate solutions in a zinc pot?

Consult the table of standard electrode potentials and suggest three substances that can oxidise ferrous ions under suitable conditions.

Calculate the potential of hydrogen electrode in contact with a solution whose pH is 10.

Calculate the emf of the cell in which the following reaction takes place: Ni(s) + 2Ag⁺(0.002 M) → Ni²⁺(0.160 M) + 2Ag(s). Given that E°cell = 1.05 V

The cell in which the following reaction occurs: 2Fe³⁺(aq) + 2I⁻(aq) → 2Fe²⁺(aq) + I₂(s) has E°cell = 0.236 V at 298 K. Calculate the standard Gibbs energy and the equilibrium constant of the cell reaction.

If a current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons would flow through the wire?

Suggest a list of metals that are extracted electrolytically.

Consider the reaction: Cr₂O₇²⁻ + 14H⁺ + 6e⁻ → 2Cr³⁺ + 7H₂O. What is the quantity of electricity in coulombs needed to reduce 1 mol of Cr₂O₇²⁻?

Write the chemistry of recharging the lead storage battery, highlighting all the materials that are involved during recharging.

Suggest two materials other than hydrogen that can be used as fuels in fuel cells.

Explain how rusting of iron is envisaged as setting up of an electrochemical cell.

Arrange the following metals in the order in which they displace each other from the solution of their salts. Al, Cu, Fe, Mg and Zn.

Given the standard electrode potentials, K⁺/K = -2.93V, Ag⁺/Ag = 0.80V, Hg²⁺/Hg = 0.79V, Mg²⁺/Mg = -2.37V, Cr³⁺/Cr = -0.74V. Arrange these metals in their increasing order of reducing power.

Depict the galvanic cell in which the reaction Zn(s)+2Ag⁺(aq) → Zn²⁺(aq)+2Ag(s) takes place. Further show: (i) Which of the electrode is negatively charged? (ii) The carriers of the current in the cell. (iii) Individual reaction at each electrode.

Calculate the standard cell potentials of galvanic cell in which the following reactions take place: (i) 2Cr(s) + 3Cd²⁺(aq) → 2Cr³⁺(aq) + 3Cd (ii) Fe²⁺(aq) + Ag⁺(aq) → Fe³⁺(aq) + Ag(s). Calculate the ΔrG° and equilibrium constant of the reactions.

Write the Nernst equation and emf of the following cells at 298 K: (i) Mg(s) | Mg²⁺(0.001M) || Cu²⁺(0.0001M) | Cu(s) (ii) Fe(s) | Fe²⁺(0.001M) || H⁺(1M) | H₂(g)(1bar) | Pt(s) (iii) Sn(s) | Sn²⁺(0.050M) || H⁺(0.020M) | H₂(g) (1bar) | Pt(s) (iv) Pt(s) | Br⁻(0.010M) | Br₂(l) || H⁺(0.030M) | H₂(g) (1bar) | Pt(s).

In the button cells widely used in watches and other devices the following reaction takes place: Zn(s) + Ag₂O(s) + H₂O(l) → Zn²⁺(aq) + 2Ag(s) + 2OH⁻(aq). Determine ΔrG° and E° for the reaction.

Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration.

The conductivity of 0.20 M solution of KCl at 298 K is 0.0248 S cm⁻¹. Calculate its molar conductivity.