Amphoteric oxide

An acidity scale has been proposed in which the difference in the acidity parameters. (aB — aA), of a metal oxide and a nonmetal oxide is the square root of the enthalpy of reaction of the acid and base.4 Thus for reaction 9.5, the enthalpy of reaction is —8fikJ mol-1 and so the a values of CaO and SiO, differ by about 9 units. Selected values are fisted in Table 9.1. Although based on the Lux-Flood concept, the values are obviously of more general interest. The most basic oxide, as expected, is cesium oxide, amphoteric oxides have values near zero (water was chosen to calibrate the scale at a value of 0.0). and the most acidic oxide is CLO,. the anhydride of perchloric acid. 

Which elements are more likely to form acidic oxides Basic oxides Amphoteric oxides ... 

The ore contains aluminium oxide (amphoteric) with large impurities of iron oxide (basic) and silicon dioxide (weakly acidic). The ore is treated with a hot 10% solution of sodium hydroxide, which reacts with the amphoteric aluminium oxide to form a solution of sodium aluminate. Iron oxide does not react as it is a base, and silicon dioxide does not... 

Strategy What type of elements form acidic oxides basic oxides amphoteric... 

Alkanolamides Alkyl sulfonates Amine oxides Amphoteric surfactants Anionic surfactants Cocoamidopropyl betaine Betaine derivatives Amido guanidines Disulfonates... 

Keywords AFM/LFM, lateral force (friction) signal, oxide (amphoteric) surfaces, pH, nanochemical imaging... 

Most oxides can be classified as acidic or basic depending on whether they produce acids or bases when dissolved in water (or whether they react as acids or bases). Some oxides amphoteric, which means that they display both acidic and basic properties. The first two oxides of the third period, Na20 and MgO, are basic oxides. For example, Na20 reacts with water to form the base sodium hydroxide ... 

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