Hydroxides are complex substances to which acids and the bases belong. The name consists of two parts – "hydra" (water) and oxide. If oxide acid, as a result of its interaction with water turns out hydroxide – acid. If oxide osnovny (not the main as sometimes mistakenly call), then and hydroxide represents the basis.
Instruction
1. In order that it is correct to write formulas which correspond to hydroxides - acids and the bases, it is necessary to have an idea of oxides. Oxides are the complex substances consisting of two elements, one of which is oxygen. Hydroxides incorporate also hydrogen atoms. It is very easy to write formulas of oxides, using the simplified scheme. For this purpose it is enough from the corresponding subtract hydroxide all molecules of water which are a part of hydroxide. If a component of acid or the basis is one molecule of water, then it is necessary to reduce amount of atoms of hydrogen by 2, and oxygen atoms on 1. If two molecules of water are a part of hydroxide, then and the amount of atoms of hydrogen and oxygen will need to be reduced by 4 and 2 respectively.
2. H2SO4, sulfuric acid. Take away 2 atoms of hydrogen and 1 atom of oxygen – receive SO3 or oxide of sulfur (VI). H2SO3, sulphurous acid. By analogy with the previous example SO2 or oxide of sulfur (IV) turns out. H2CO3, coal acid. CO2 or carbon oxide (IV) .H2SiO3, silicon acid is formed. Therefore, SiO2 or oxide of silicon.Ca (OH) 2, calcium hydroxide will turn out. Subtract a molecule of water and there will be CaO or oxide of calcium.
3. In some formulas of hydroxides there is an odd amount of atoms of hydrogen, and therefore doubling is required. Besides, also other elements which are a part of hydroxide are exposed to doubling then, by analogy, all formed water.NaOH molecules, sodium hydroxide are subtracted. Double amount of atoms of each element and receive Na2O2H2. Subtract a molecule of water and there will be Na2O or oxide of sodium.Al (OH) 3, aluminum hydroxide. Double amount of atoms – Al2O6H6. Subtract three formed molecules of water and Al2O3, aluminum oxide will turn out.
4. HNO3, nitric acid. Double quantity of each element – receive H2N2O6. Subtract from it one molecule of water and N2O5 – nitrogen oxide (V) will turn out. HNO2, nitrogenous acid. Make doubling of number of each element – receive H2N2O4. Subtract from it one molecule of water and N2O3 – nitrogen oxide (III) will turn out. H3PO4, orthophosphoric acid. Double quantity of each element – receive H6P2O8. Subtract from it three molecules of water and P2O5 – oxide of phosphorus (V) will turn out. HMnO4, manganic acid. Execute doubling of amount of atoms and receive H2Mn2O8. Subtract a water molecule (2 atoms of hydrogen and 1 atom of oxygen), as a result there will be Mn2O7 - oxide of manganese (VII).