14 Faraday

1833 Faraday, a student of Davy, introduced the vocabuiary of eiectrochemistry (eiectrode, anion-anode and cation-cathode) and observed the iink between the mass of compound produced or consumed and the amount of charge passed (iaws of eiectroiysis). 

1836 DANiELL made up the two-compartment battery caiied the Daniell ceii, which is stiii the main reference example given of an electrochemical battery In a number of educational books. Anyway this is its oniy use since the eiectric power that this battery can provide is guite negiigibie. 

1837 JACOBi invented galvanopiasty, which has numerous appiications today. 

1839 Grove discovered the reversibiiity of water eiectroiysis reactions, and iaid the basis of the first fuei ceii, which was not to undergo any significant development until the NASA program In the 1960 s. 

1859 Plante invented the lead-acid battery, which is still widely used because it can deiiver high ieveis of electric power at a low cost. Of course, its manufacturing process underwent many improvements, but its main principie remained unchanged. 

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Benzene was first isolated by Faraday in 1825 from the liquid condensed by compressing oil gas. It is the lightest fraction obtained from the distillation of the coal-tar hydrocarbons, but most benzene is now manufactured from suitable petroleum fractions by dehydrogenation (54%) and dealkylation processes. Its principal industrial use is as a starting point for other chemicals, particularly ethylbenzene, cumene, cyclohexane, styrene (45%), phenol (20%), and Nylon (17%) precursors. U.S. production 1979 2-6 B gals. 

We now consider briefly the matter of electrode potentials. The familiar Nemst equation was at one time treated in terms of the solution pressure of the metal in the electrode, but it is better to consider directly the net chemical change accompanying the flow of 1 faraday (7 ), and to equate the electrical work to the free energy change. Thus, for the cell... 

The standard states of Ag and of Ag (aq) have the conventional definitions, but there is an ambiguity in the definition of the standard state of e. Suppose that a reference electrode R is positioned above a solution of AgN03, which in turn is in contact with an Ag electrode. The Ag electrode and R are connected by a wire. Per Faraday, the processes are... 

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