Chemistry is important! … ”you can remain ignorant of matter, to allow changes to occur without considering the effect on your life, or allow others to decide what changes will be made in the matter that makes up your world and that of future generations” 1 1 Hall, T. et al, Chemistry, DC Heath and company, Ma. 1993, p.5.

Nomenclature of Binary Compounds by Marta de Ortiz de Zevallos n To understand the formulas and their names is to learn the “universal language of Chemistry”.

The Periodic Table n Metals are at the left (red) n Non-metals at the right, except for H (blue)

What are binary compounds? n Examples: n NaCl = sodium chloride. n CO 2 = Carbon dioxide. Binary compounds are chemical compounds formed only by two elements.

There are two types of binary compounds...

Binary Ionic Compounds (a metal and a non metal) n n The metal looses electrons becoming positive (+) n n The non metal gains electrons becoming negative (-) I’m hit, I’m hit, I’ve lost an electron!!! Are you sure? I’m POSITIVE!!! + elements/webelements/elements/text/key/Na.html

Positive and negative ions attract each other... n Perhaps one of you gentlemen n would mind telling me n just what is it outside the window n that you find so attractive….?

What is the charge? Group 1: 1+ Group 17: Group 2: 2+ Group 13: 3+ Group 16: 2- Group 15: 3- Group 14: 4- ? ???

For example, how do we write the formula of a compound between calcium and fluorine ? n n Write the positive element (metal) first with its charge (top right) n Ca 2+ n Then write the negative element (non-metal) with its charge F 1- Do a cross multiplication Ca 2+ F 1-

CaF 2 Is the right ANSWER!

Simplify if it is necessary For example, suppose you want to write the formula of the compound formed between Gallium and Nitrogen… Ga 3+ N 3- Ga 3 N 3 GaN ANSWER!

Do you want to try by yourself? Write the formulas of the ionic compounds formed between: 1) Lithium and Oxygen Li 2 O 2) Potassium and Chlorine KCl 3) Aluminum and Sulfur Al 2 S 3 4) Barium and Carbon Ba 2 C

How do we name these compounds? Name the metal first Then the “root” of the non-metal Finally add the ending “ IDE ”  Example  Li 2 O Metal= Lithium Non-metal= Oxygen Root=Ox Answer: Lithium Oxide

Let’s practice again… write the names of: CaF 2 Calcium Floride GaN Gallium Nitride KCl Potassium Chloride Al 2 S 3 Aluminum Sulfide Ba 2 C Barium Carbide

But there are some metals that have more than one possible charge Copper can be Cu 1+ or Cu 2+ Mercury can be Hg 1+ or Hg 2+ Iron can be Fe 2+ or Fe 3+ Cobalt can be Co 2+ or Co 3+ Tin can be Sn 2+ or Sn 4+ Lead can be Pb 2+ or Pb 4+

How do you combine for example Iron, Copper, and Lead with Oxygen? You have two possibilities for each: Fe 2+ +O 2- -> FeO Fe 3+ + O 2- ->Fe 2 O 3 Cu 1+ + O 2- -> Cu 2 O Cu 2+ + O 2- ->CuO Pb 2+ + O 2- ->PbO Pb 4+ + O 2- ->PbO 2

What do we do in this case?  Between the metal and the non metal, write the charge of the metal, in roman numerals and between parenthesis. FeO is Iron (II) oxide Fe 2 O 3 is Iron (III) oxide

Ready to practice? Write the formula of: Iron (II) Chloride FeCl 2 Iron (III) Nitride FeN Mercury (I) Fluoride HgF Easy?

Now the other way around ? ? ? ? Write the formula of the following compounds: # CuS # Copper (II) Sulfide # CoCl 3 # Cobalt (III)Chloride # Sn 3 N 4 # Tin (IV) Nitride

Binary molecular or covalent compounds... n n Name the first element + the root of the second + ide… n n But, before each element, use prefixes to indicate the amount of atoms of each type.. Prefixes mono 1 di 2 tri 3 tetra 4 penta 5 hexa 6 hepta 7 octa 8 nona 9 deca 10 Note: don't use mono for the first element

How do we do that??? Let’s see some examples: CO 2 Carbon dioxide N2O5 N2O5 Dinitrogen pentaoxide P2O7 P2O7 Diphosphorous heptaoxide

Let's try the other way around... CO Carbon Monoxide N2O5 N2O5 Dinitrogen pentoxide CCl 4 Carbon tetrachloride NO 2 Nitrogen dioxide

Remember!!! Binary compounds (two elements) Can be ionic (metal+non-metal) or molecular (two non-metals) For molecular compounds use prefixes indicating the amount of atoms of each type Remember!!!Remember!!! Dinitrogen trioxide N 2 O 3

In ionic, the metal can have one or more than one charge If it has only one, just name: Metal+non-metal+ide NaCl = Sodium chloride SnO 2 =Tin (IV) oxide If it has more than one charge, use roman numerals to indicate the charge of the metal.

Good Job!!! If you want more practice go to enclature/Nomenclature.html