Oxides - a substance in which the molecules consist of an oxygen atom with a degree of oxidation - 2 and the atoms of a second element.
oxides are formed by the direct reaction between oxygen and another substance or indirectly - by the decomposition of bases, salts, acids.Such type compounds are very common in nature, and can exist in the form of gas, liquid or solid.The Earth's crust are also oxides.For example, sand, rust, carbon dioxide, and even usual water - are all examples of the oxides.
There are like salt-forming and nesoleobrazuyuschie oxides.Salt-forming by chemical reaction yield salts.These include non-metals and metal oxides which react with water to form acid, and a reaction with a base - the salt, normal and acidic.By the salt-forming include, for example, copper oxide.
Accordingly, to obtain the salt of nesoleobrazuyuschih impossible.As an example, carbon dioxide, dinitrogen oxide and nitrogen oxide.
salt-forming oxides are divided, in turn, on the basic, acid and amphoteric.We'll talk more in detail about the main.
Thus, the main oxides - is of some metals oxides, hydroxides appropriate that belong to the class bases.That is, by reacting with an acid such substances form water and salt.For example, it K2O, CaO, MgO, and so forth. Under normal conditions, the basic oxides are solid crystalline formations.Degree oksileniya metal in such compounds is usually not more than two or three rare.
chemical properties of basic oxides
1. Reaction with acid
It was in reaction with an acid oxide exerts its basic properties, so such experiments can prove one or another type of oxide.If you form a salt and water - so this is the main oxide.Acidic oxides such interaction acid form.A can be amphoteric or acidic, or basic properties - it depends on conditions.These are the main differences between a nesoleobrazuyuschih oxides.
2. Reaction with water
In interaction with water enter those oxides of metals which are formed of a number of electrical voltage, facing magnesium.Upon reaction with water, they form soluble bases.This group of alkaline earth oxides and alkali metals (barium oxide, lithium oxide, etc.).Acidic oxides in water to form acid, and amphoteric water do not react.
3. Reaction with acid oxides and amphoteric
opposite in their chemical nature oxides react with each other, forming a salt.For example, basic metal oxides can react with the acid but do not respond to other members of their group.The most active ones are oxides of alkali metals, alkaline-earth and magnesium.Even under normal circumstances, they are fused with solid amphoteric oxides, solid and gaseous acid.Upon reaction with acidic oxides form a corresponding salt.But
basic oxides of other metals less reactive and hardly reacts with the gaseous oxides (acidic).They can only enter into the addition reaction by alloying with solid acidic oxides.
4. Redox properties
active alkali metal oxides do not show marked recovery or oxidizing properties.In contrast, the oxides are not as active metals are recovered coal with hydrogen, ammonia or carbon monoxide.
Getting basic oxides
1. hydroxides Decomposition: When heated, the insoluble base decompose to water and basic oxide.
2. The oxidation of metals: alkali metal during the combustion of oxygen forms a peroxide, which then forms the reduction of the basic oxide.
