rules in naming organic compound

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1. R U L E S I N N A M I N G I N O R G A N I C C O M P O U N D Prepared by: STEFFHANIE D. TABLIGA

2. BINARY MOLECULAR COMPOUNDS When a pair of elements form more than one type of covalent compound, Greek prefixes are used to indicate how many of each element are in a compound. The more electronegative element is written last and its ending is changed to –ide.

3. EXAMPLES: N 2 O = Dinitrogen monoxide NO = Nitrogen monoxide N 2 O 3 = Dinitrogen trioxide N 2 5 = Dinitrogen pentoxide

4. SOME OF THE GREEK PREFIXES ARE GIVEN BELOW: Mono = 1 Di = 2 Tri = 3 Tetra = 4 Penta = 5 Hexa = 6 Hepta = 7 Octa = 8

5. IONIC COMPOUNDS Metals give up electrons to form positively charged cations . Non-metals gain electrons to form negatively charged anions. Ionic compounds are formed from the C oulombic interaction between cations and anions.

6. WHEN WE NAME AN IONIC COMPOUND, WE WRITE: The name of the cation comes first followed by the name of the anion, changing the name of the anion to end in –ide for monotomic anions are not altered. EXAMPLES: NaCl = Sodium chloride Znl 2 = Zinc iodide NaNO 3 = Sodium nitrate

7. In those cases where the metal can form cations of differing charges the positive charge is given by a roman numeral in parentheses. EXAMPLES: CuO = Copper (II) Oxide Cu 2 O = Copper (I) Oxide Cr 2 O 3 = Chromium (III) Oxide

8. OXYANIONS Oxyanions are those polyatomic anions containing oxygen. There are a large number of oxyanions, which makes it difficult to remember of their names. Fortunately there is a set of rules that makes this task much easier.

9. EXAMPLES: ClO 4 = Percholorate ion ClO 3 = Chlorate ion ClO 2 = Chlorate ion ClO = Hypochlorate ion

10. ACIDS A simplistic definition of an acid is a ccompound that dissolves in water to release H+ ions. The ending – ate is used for the most common oxyanion of a given element. NO 3 = Nitrate ion

11. SO 4 2 = Sulfate ion CO 3 2 = Carbonate ion PO 4 3 = Phosphate ion ClO 3 = Chlorate ion

12. The ending – ite is used for the oxyanion with the same charge, but one less oxygen than the – ate oxyanion. NO 2 = Nitrite ion SO 3 2 = Sulfite ion PO 3 3 = Phosphite ion ClO 2 = Chlorite ion

13. The prefix per- is used if there is an oxyanion with the same charge but one more oxygen than the – ate oxyanion, while the prefix hypo- is used. A simplistic definition of an acid is a compound that dissolves in water to release H+ ions to an oxyanion to balance its charge. The rules for naming simple acids are based on the names of the anions, they are given below.

14. When the anion ends in – ide , change the ending to – ic and add the prefix hydro- to derive the name of the acid. Anion = chloride ( Cl - ) hydrochloric acid ( HCl ) Anion = bromide (Br-) hydrobromic acid ( HBr ) Anion = sulfide (s2) hydrosulfuric acid (H 2 S)

15. When the anion ends in – are, change the ending to – ic to derive the name of the acid. Anion = chlorate (CLO 3 ) chloric acid (HCLO 3 ) Anion = sulfate (SO 4 2) sulfuric acid (H 2 SO 4 ) Anion = nitrate (NO 3 ) nitric acid (HNO 3 ) When the anion ends in – ite , change the ending to – ous to derive the name of the acid.

16. Anion = phosphate (PO 3 3) P hosphorus acid (H 3 PO 3 ) Anion = chlorite (Cl0 2 ) Chlorous acid (HClO 2 ) Anion = hypochlorite ( ClO ) Hypochlorous acid ( HClO )

17. THANK YOU   AND GOD BLESS  