Naming+Hydrates+and+Naming+Compounds+Using+the+Prefix+System

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=__ Naming Hydrates and Naming Compounds Using the Prefix System __= = = = Important prefix to be known ​ = = --- =

= Covalent compounds and ionic compounds have different naming ways. When non-metal and non-metal form a covalent compound, their naming requires prefix system to show how many atoms are in the compound. =
 * ** Naming covalent compounds by using prefix system. **




 * 1) Each compound name contains two words, and each word with a prefix.
 * 2) The order of writing elements in a compound is usually from left to right on the Periodic Table.
 * 3) Write the name of the first element with a prefix to represent the number of atoms in the molecule.
 * 4) Write the name of the second element with the end "ide" and a prefix number
 * 5) When the first element has only one atom, we do not write "mono" in front of its name.( Ex. CO2-carbon dioxide)

** EXAMPLES: ** Si2l6=disilicon hexaiodide N2O3=dinitrogen trioxide S4N2=tetrasulphur dinitride ** CS2=carbon disulphide P2O6=diphosphorus hexoxide **
 * SO=sulphur monoxide
 * N2O4=dinitrogen tetraoxide


 * ** Naming hydrates by using prefix system **

**Hydrate** : Molecules which include water nolecules in their crystal structures are called **__HYDRATES.__ (from textbook Pg.72)**

EX.Na2S*9H2O nine water molecules are attached to every Na2S molecule.

1. Each hydrate name contains two words, and the second word with a prefix. 2. Write the name of the part before water molecules. 3. Write the name of water molecules with a prefix number to represent the number of water molecules. (Ex. 5H2O= pentahydrate) **EXAMPLES: FeBr3*6H2O=iron(lll) bromide hexahydrate** ** Ca(NO3)2*4H2O=calcium nitrate tetrahydrate Na2S*9H2O=sodium sulphide nonahydrate Na2SO4*10H2O=sodium sulphate decahydrate **
 * AL2O3*3H2O=aluminum oxide trihydrate**
 * CuSO4*5H2O=copper(ll) sulphate pentahydrate**