Metal dissolved in acids

In aqueous media lutetium occurs as tripositive Lu3+ ion. All its compounds are in +3 valence state. Aqueous solutions of all its salts are colorless, while in dry form they are white crystalline solids. The soluble salts such as chloride, bromide, iodide, nitrate, sulfate and acetate form hydrates upon crystallization. The oxide, hydroxide, fluoride, carbonate, phosphate, and oxalate of the metal are insoluble in water. The metal dissolves in acids forming the corresponding salts upon evaporation of the solution and crystallization. 

In the case of solution of a solid in a limited volume of solution the rate of solution will follow a unimolecular law, thus in the case of metals dissolving in acids, or salts in water, for a constant area of interface the rate will be expressed by the equation dx... 

The Ncrnst equation was given before (Eq. 10.115), and in this chapter the effect of pH on the reduction potential of the hydrogen ion has been mentioned, but the effect in general should be emphasized. There are several types of reactions in which concentrations of the reactants and products affect the stability of various oxidation states. This can be understood through application of the Nemst equation. The reduction potential of hydrogen will vary with the concentration of the hydrogen ion hence the commonly known fact that many reasonably active metals dissolve in acid but rot in base. 

The reactions in which metals dissolve in acids or alkalis are also reductions of the dissolving agents, as ... 

VII.24 LITHIUM, Li (Ar 6 94) Lithium is a silver-white metal it is the lightest metal known (density 0-534 g ml-1 at 0°) and floats upon petroleum. It melts at 186°C. It oxidizes on exposure to air, and reacts with water forming lithium hydroxide and liberating hydrogen, but the reaction is not so vigorous as with sodium and potassium. The metal dissolves in acids with the formation of salts. The salts may be regarded as derived from the oxide, Li20. 

The fourth class of phenomena, the precipitation of metals from their dissolution in acids by fixed and volatile alkali salts, was Louis Lemery s main interest. This was precisely the problem his father had labeled as one of the most difficult questions to resolve well in philosophy already in 1675. This type of precipitation consisted yet of two kinds. In the first, the metal dissolved in acid was precipitated as subtle powder by an alkali. In the second, the metallic solution turned, upon the mixture... 

Indium metal dissolves in acids, but does not react with oxygen at room temperature. At higher temperatures, it combines with oxygen to form indium oxide (10203). 

Boyle was not alone in attempting to apply the atomic hypothesis to chemistry. Nicolas Lemery (1645-1715) suggested that the properties of substances could be explained in terms of the shapes of their atoms. The sharp taste of acids was due to their atoms being pointed and able to prick the tongue. Metals dissolved in acids because the points of the acid particles were able to break up the aggregation of metal particles. Lemery described his theories in his book Cours de Chymie published in 1675 (Figure 3.3). Lemery s book was also a comprehensive treatise on the practical chemical knowledge of the time. It ran to many editions and was very influential. 

The results of the experiments on the composition of water were very important. They enabled Lavoisier to explain the source of the inflammable gas evolved when many metals dissolve in acids (which had previously caused him difficulty, see p. 444) and during the fermentation of vegetable matters, and also why and in what cases water burns combustible bodies or augments their combustion when it has begun. He also explained how water operates in the calcination of metals and how it is decomposed and formed in a large number of chemical operations. The further applications of this discovery were later made to the abundant formation of water in the combustion of spirit of wine and oils, the production of carbonic acid in the action of water on red-hot carbon, the formation of water in the combustion of charcoal... 

The nature of the reactants It makes sense that various substances react with other substances differently. For example, metals dissolve in acids at different speeds. The exhaust gases from an automobile enter the atmosphere where they react with other gases in the atmosphere at different rates. 

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