Chemical properties of substance are an ability to change the structure during chemical reactions. Reaction can proceed either in the form of self-decomposition, or in interaction with other substances. Properties of substance depend not only on its structure, but also on structure. There is a characteristic example: both ethyl alcohol, and ethyl air have an identical empirical formula C2H6O. But chemical properties at them different. As a structural formula of CH3-CH2-OH alcohol, and air - CH3-O-CH3.
Instruction
1. There are two main ways of determination of properties: theoretical and practical. In the first case the idea of properties of substance is done, proceeding from its empirical and structural formula.
2. If this simple substance, that is consisting of atoms only of one element for the answer to this question is enough to look in Mendeleyev's table. There is an accurate regularity: the is more left and below the element in the table is located, the stronger it expressed metal properties (reaching a maximum at France). Respectively, the is more right and is higher, the nonmetallic properties are stronger (reaching a maximum at fluorine).
3. If substance belongs to the class of oxides, its properties depend on to what element oxygen is connected. There are main oxides formed by metals. Respectively, they show properties of the bases: react with acids, forming salt and water; with hydrogen, being restored to metal. If the main oxide is formed by alkaline or alkaline-earth metal, it reacts with water, forming alkali, or with acid oxide, forming salt. For example: SaO + H2O = Sa (IT) 2; K2O + CO2 = K2CO3.
4. Acid oxides react with water, forming acid. For example: SO2 + H2O = H2SO3. Also they react with the bases, forming salt and water: CO2 + 2NaOH = Na2CO3 + H2O.
5. If oxide is formed by an amphoteric element (for example, aluminum, a germaniye, etc.), he will show as the main, and acid properties.
6. When substance of more complex structure, the conclusion about its properties do, considering a number of factors. First of all, proceeding from existence and the number of functional groups, that is those sites of a molecule which directly forms a chemical bond. For the bases and alcohols, for example, it is a hydroxyl group – IT, for aldehydes – COH, for carbonic acids – SOON, for ketones – WITH, etc.
7. The practical way as it is easy to understand from the name, consists in check of chemical properties of substance by practical consideration. It is subjected to interaction with certain reagents under various conditions (temperature, pressure, in the presence of catalysts, etc.) and watch what will be result.