P. Sci. Unit 9 Chemical Compounds Chapter 6

Part 2 Compound Names and Formulas

Binary Compounds Most of the compounds that you will have to name will have only 2 elements (called binary – bi meaning 2) or an element and a polyatomic ion. NaCl CaCl 2 P2O5P2O5 NaNO 3 Al(ClO 3 ) 3 NaCl CaCl 2 P2O5P2O5 NaNO 3 Al(ClO 3 ) 3

Naming Compounds First you have to identify what type of compound it is : –Ionic – metal and non-metal. –Covalent – two non-metals –Polyatomic - both NaCl N2O4N2O4 CaCO 3

Ionic Compounds 1.Write the name of the metal (cations = + ion) Examples: Na = Sodium Ca = Calcium Al = Aluminum

Ionic compounds cont. 2.Write the name of the non- metal (anion = - ion) but change the ending to “ide”. Examples: Chlorine – Chloride Fluorine – Fluoride Oxygen – Oxide Sulfur – Sulfide Phosphorus – Phosphide Iodine- Iodide

Examples NaCl = Sodium chloride CaI 2 = Calcium iodide CsBr= Cesium bromide Al 2 O 3 = Aluminum Oxide For ionic compounds – pay no attention to the subscripts.

Now you try Name the following ionic compounds. –LiF = –MgO = –SrCl = –K 2 S = –Ca 3 N 2 =

Answers –LiF = Lithium fluoride –MgO = Magnesium oxide –SrCl = Strontium chloride –K 2 S = Potassium sulfide –Ca 3 N 2 = Calcium Nitride

Covalent Compounds 1.First Name a)If there is only one atom of this element, just write the name of the element. Example: N = Nitrogen C = Carbon P = Phosphorus

Covalent compounds cont. 1.First Name cont. b)If there is more than one atom of the element, write the name of the element with the pre-fix that tells how many atoms are there.

Pre-fixes 1 – mono 6 – hexa 2 – di 7 – hepta 3 – tri 8 – octa 4 – tetra 9 – nona 5 – penta 10 – deca

Examples:H 2 – di-hydrogen C 3 – tri-carbon Br 4 – tetra-bromine

Covalent compounds cont. 2.Second Name – Always has a prefix. a)Always starts with a prefix that tells how many atoms are there. (even if there is only one)

2.Second Name cont. b) ends in “ide” Covalent compounds cont. Examples : CO – carbon monoxide CO 2 – carbon dioxide CO 3 – carbon trioxide

Now you try Name the following covalent compounds. – NO 2 = –PBr 3 = – AsCl = –H 2 O = –H 2 O 2 =

Answers – NO 2 = Nitrogen dioxide –PBr 3 = Phosphorus tribromide – AsCl = Arsenic monochloride –H 2 O = Di-hydrogen monoxide –H 2 O 2 = Di-hydrogen dioxide

Polyatomic Ions Compounds with both ionic and covalent bonds. Acts the same as any other ion.

Polyatomic ions cont. Examples: –Ammonium NH 4 + –Hydroxide OH - –Sulfate SO 4 +2 –Carbonate CO 3 -2

Polyatomic compounds Follow step one for ionic compounds. ( Write the name of the metal ) Write the name of the polyatomic ion ( do not change to “ide”) Examples: NaNO 3 = Sodium nitrate Al(ClO 3 ) 3 = Aluminum chlorate