Define the following - activity, activity coefficient and the mean activity coefficient of ions in solution.

Physical Chemistry IV (Electrochemistry and Photochemistry)

GENERAL OBJECTIVES:

1. Understand the behaviours of ions in solution

2. Understand the nature of electrochemical cells

3.Understand the phenomenon of ion transport and molecular diffusion.

4.Understand photochemical reactions

1.1 Define the following - activity, activity coefficient and the mean activity coefficient of ions in solution.

1.2 Describe the ionic atmosphere.

1.3 State the role of ionic atmosphere in determining the value of the mean activity coefficient.

1.4 State the form of a shielded coulomb potential.

1.5 Define ionic strength.

1.6 State and derive the DebyeHuckel limiting law for the mean activity coefficient.

1.7 Explain how the DebyeHuckel limiting law may be extended to more concentrated solutions.

1.8 Define the electrochemical potential of an ion.

1.9 Derive an expression for the potential difference across an interface in terms of the standard potential difference and the activity of ions.

1.10 Derive an expression for the potential difference across a gas/inert metal electrode.

1.11 Derive an expression for the potential difference across a metal/insoluble salt/ion electrode.

1.12 Describe the construction of metal/insoluble salt/ion electrode.

1.13 Derive an expression for the potential difference at a redox electrode (oxidation potential).

1.14 Obtain Ecell from data using the expression in 1.14 above.

1.15 Describe the formation of a liquid junction potential.

1.16 Derive an expression for the potential difference across a membrane.

1.17 Describe the construction of a cell with a liquid junction and a cell without a liquid junction.

2.1 Define thermodynamic reversibility of an electrochemical cell.

2.2 Define electrode potential and describe the sign convention.

2.3 Relate the e.m.f of a cell to the spontaneous direction of change of the cell reaction.

2.4 Define the term standard e.m.f.

2.5 Derive the Nernst equation for the concentration dependence of the e.m.f. of a cell.