Each student met with the concept of "oxide" in chemistry lessons. From this word alone, the object began to seem something indescribably terrible. But there is nothing wrong here. Higher oxides are substances that contain compounds of simple substances with oxygen (in the oxidation state -2). It is worth noting that they react with:
- O2 (oxygen), if the element is not in the highest CO. For example, SO2 reacts with oxygen (because CO is +4), and SO3 - does not (because it costs in the highest oxidation state +6).
- H2 (hydrogen) and C (carbon). Only some oxides react.
- Water if soluble alkali or acid is obtained.
All oxides react with s alts and non-metals (except for the above substances).
It is worth noting that some substances (for example, nitric oxide, iron oxide and chlorine oxide) have their own characteristics, that is, their chemical characteristics may differ from other substances.
Classification of oxides
They are divided into two branches: those who can form s alt, and those whothey cannot form it.
Examples of formulas for higher oxides that do not form s alts: NO (nitric oxide is bivalent; colorless gas formed during thunderstorms), CO (carbon monoxide), N2 O (nitric oxide monovalent), SiO (silicon oxide), S2O (sulfur oxide), water.
These compounds can react with bases, acids and s alt-forming oxides. But when these substances react, s alts are never formed. For example:
CO (carbon monoxide) + NaOH (sodium hydroxide)=HCOONa (sodium formate)
S alt-forming oxides are divided into three types: acidic, base and amphoteric oxides.
Acidic higher oxide is a s alt-forming oxide that corresponds to an acid. For example, hexavalent sulfur oxide (SO3) has a corresponding chemical compound - H2SO4. These elements react with basic and amphoteric oxides, bases and water. A s alt or acid is formed.
- With alkaline oxides: CO2 (carbon dioxide) + MgO (magnesium oxide)=MgCO3 (bitter s alt).
- With amphoteric oxides: P2O5 (phosphorus oxide)+ Al2 O3 (aluminum oxide)=2AlPO4 (aluminum phosphate or orthophosphate).
- With bases (alkalis): CO2 (carbon dioxide) + 2NaOH (caustic soda)=Na2CO 3 (sodium carbonate or soda ash) + H2O (water).
- With water: CO2 (carbon dioxide) +H2O=H2CO3 (carbonic acid, after the reaction instantly decomposes into carbon dioxide and water).
Acid oxides do not react with each other.
Basic higher oxide is a s alt-forming metal oxide, which corresponds to the base. Calcium oxide (CaO) corresponds to calcium hydroxide (Ca(OH)2). These substances interact with acidic and amphoteric oxides, acids (with the exception of H2SiO3, since silicic acid is insoluble) and water.
- With acidic oxides: CaO (calcium oxide) + CO2 (carbon dioxide)=CaCO3 (calcium carbonate or ordinary chalk).
- With amphoteric oxide: CaO (calcium oxide) + Al2O3 (aluminum oxide)=Ca(AlO 2)2 (calcium aluminate).
- With acids: CaO (calcium oxide) + H2SO4 (sulfuric acid)=CaSO4 (calcium sulfate or gypsum) + H2O.
- With water: CaO (calcium oxide) + H2O=Ca(OH)2 (calcium hydroxide or lime slaking reaction).
Do not interact with each other.
Amphoteric higher oxide is the oxide of an amphoteric metal. Depending on the conditions, it can show basic or acidic properties. For example, the formulas of higher oxides that exhibit amphoteric properties: ZnO (zinc oxide), Al2O3 (alumina). React amphotericoxides with alkalis, acids (also excluding silicic acid), basic and acidic oxides.
- With bases: ZnO (zinc oxide) + 2NaOH (sodium base)=Na2ZnO2 (double s alt of zinc and sodium)+ H2O.
- With acids: Al2O3 (aluminum oxide) + 6HCl (hydrochloric acid)=2AlCl3 (aluminum chloride or aluminum chloride) + 3H2O.
- With acidic oxides: Al2O3 (aluminum oxide) + 3SO3 (hexavalent sulfur oxide)=Al2(SO4)3 (aluminum alum).
- With basic oxides: Al2O3 (aluminum oxide) + Na2 O (sodium oxide)=2NaAlO2 (sodium aluminate).
Elements of higher amphoteric oxides do not interact with each other and with water.