The Electrolytic Dissociation Theory with Sopme of Its Applications (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905. Excerpt: ..., CHAPTER II The Law Of Mass Action And The Chemical Behavior Of Electrolytes Reversible Reactions And The Effect Of Mass 21. In order to understand the applications of the Law of Mass Action, it is first necessary to know what is meant by a reversible reaction. A familiar example is to be found in the action of steam upon iron filings. If iron filings are introduced into a tube and brought to a high temperature, and steam is then passed over them, the iron will be changed to iron oxide, and hydrogen will be liberated according to the reaction 3Fe-j-4H20 Fe304 + 4H2. If, however, the tube is kept at the same temperature and hydrogen is passed through instead of steam, the iron oxide will be reduced to iron, Fe304-f4H2 3Fe-f-4H20; that is, the first reaction is reversed. It should be noted that in the first of these two cases the steam is supplied freely, and the hydrogen, which is the product of the reaction, is forced out of the tube, while in the second case the ready supply of hydrogen displaces the steam which is formed from the reduction of the iron oxide. Suppose, however, that the conditions are so altered that the gaseous product of the reaction cannot escape, as would be the case if the reactions were carried out in two sealed tubes, one of which had been previously charged with iron and water vapor, the other with iron oxide and hydrogen. If these tubes were heated the reaction in each would begin as described above for the open tube; but in the first tube the amount of water vapor would gradually diminish and that of the hydrogen increase, while in the second the concentration of the hydrogen would diminish as that of the water vapor increased. It is easy to see that a point would be reached in each at which the accumulation of the body which ...