ITIS Majorana Brindisi

Chemistry course

Voltaic cells

Teacher

Gioacchino Margarito

Chemistry and Electricity“I have the pleasure of communicating to you, Sir, and through you to the Royal Society, some striking results at which I have arrived in pursuing my experiments on the electricity excited by the simple mutual contact of metals of different sorts...” Alessandro Volta (1801) 

 

 

 

 

Alessandro Volta Luigi Galvani

What is electrochemistry? Electrochemistry is the study of reactions in which charged particles (ions or electrons) cross the interface between two phases of matter, typically a metallic phase (the electrode) and a conductive solution, or electrolyte. A process of this kind can always be represented as a chemical reaction and is known generally as an electrode process.

Potential differences at interfaces

Cell structure and electrode reactions

Electromotive force

The Nernst equation

for a cell at 25 °C

a= activity of the reactants and products∆E°= cell electromotive force standard (25°C, 1atm, a=1), whose values are tabulatedn= number of electrons exchanged in the reaction

Practical applications of voltaic cells

We use a variety of types of voltaic cell in everyday life, such as:

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