Chemical Nomenclature How to write and say chemical formulas General Chemistry 10-11

Elements Elements are said with just their name Mg = magnesium Ca = calcium Some elements never exist by themselves These are called diatomic molecules There are seven of them and they make a seven on the periodic table

The Diatomic Molecules These would still be said by their elemental name but would be written with a subscript of 2 N2 O2 F2 Cl2 Br2 I2 H2

Compounds Most elements are not found separately but combined in a compound with something else The reason for this is the octet rule We want 8…eight is great!

Octet Rule Noble gases are what all elements aspire to be like electronically These elements have 8 electrons in highest energy level

Ionic Bond Atoms will either give up or take electrons to get to have eight in their highest energy level Na Cl

Hey, can you help me out and gimme an electron? Na Cl

Why certainly, I have one I don’t want anyway. Na Cl

Give up/take away electrons Na Cl

Charges Sodium now has a +1 charge since it has lost an electron Chlorine a minus charge since it gained an electron Na Cl + -

Ionic Bond - NaCl 4Eva + Na Cl Opposites attract, so a bond is formed between the two of them. Na Cl + - (or until water breaks us apart) NaCl 4Eva

Ionic Compound The combination of Na+ and Cl- form the compound NaCl An ionic compound will always consist of: A metal ion (also called a cation, the + one) A non-metal ion (also called an anion, the - one) CATION ALWAYS COMES BEFORE THE ANION; both in the name and the formula

Naming Ionic Compounds When naming ionic compounds Just say the name of the metal For the non-metal, drop the ending and add -ide to it. NaCl = sodium chloride

Practice Problem #1 Name the following ionic compounds ZnO Zinc oxide LiBr Mg3N2 BaS K3P Zinc oxide Lithium bromide Magnesium nitride Barium sulfide Potassium phosphide

Determining metal and non-metal charge Where are the metals on the periodic table? Metals always have what charge? Where are the nonmetals? Nonmetals always have what charge? We’ll see the charges of the different families on the following slide.

Using the periodic Table to find an ion’s charge +1 +2 -1 -2 -3 -4 We’re going to forget all about the middle of the table for now.

Combining metals and nonmetals When combining a metal and a non-metal, the overall charge of the compound must be zero. You must balance out the overall charge!

Combining metals and nonmetals Take for instance calcium nitride. What is the charge of the calcium ion? What is the charge of the nitride ion?

Combining metals and nonmetals Ca+2 means each calcium ion has 2 more electrons than it wants N-3 means each nitride ion needs 3 more electrons. Ca N

Hey buddy, can you spare 3 electrons?

Sorry, I only have two. Ca N

Maybe I can help! N Ca

Ca N

HEY, What about me? Ca +2 N -3 YEAH! YEAH!

Hang loose, man. I’ll get one of my buddies. Ca +2 N -3

YO, YO, YO. Your hero has arrived. N Ca +2 N -3

N -3 -1 YEAH! +2 Ca +2 Ca

I still need two more. N -3 -1 +2 Ca +2 Ca

I need to get rid of two more. Ca I need to get rid of two more. N -3 -1 +2 Ca +2 Ca

Ca N -3 -1 +2 Ca +2 Ca

The ions found they were still attracted to one another due to their opposing charges. And they all lived happily ever after. Ca +2 N -3

Now is the time to learn “SWITCHY SWITCHY” and reduce! Practice Problem #2 Give the formulas for the following compounds Beryllium iodide Potassium sulfide Magnesium oxide Strontium fluoride BeI2 K2S MgO SrF2 Now is the time to learn “SWITCHY SWITCHY” and reduce!

Transition Metals The middle block of elements All cations Most can take on multiple charges Some Exceptions Zn = +2 Ag = +1

Transition metal compounds In order to tell what charge a transition metal has, put its charge in parenthesis For instance Copper (II) Oxide means… the copper ion here has a +2 charge For instance Copper (I) Oxide means… the copper ion here has a +1 charge What are the formulas of these two ionic compounds?

Practice Problem #3 Give the formula of the following compounds: Tungsten (IV) Chloride Gold (III) phosphide Tin (II) fluoride Zinc sulfide WCl4 AuP SnF2 ZnS

Polyatomic Ions Sometimes, atoms get together but can’t quite get to an overall zero charge. This is where they become a polyatomic ion They’re still a charged particle (mostly anions) so they can combine with an opposing charged ion to produce a compound Naming is easy, we just say the name of the polyatomic ion With polyatomic ions we don’t have to change the ending

Ionic Compounds involving a polyatomic ion H [ 1N = -5 4H = -4 Total -9 One extra electon

Ionic Compounds involving a polyatomic ion H [ Cl

Ionic Compounds involving a polyatomic ion H [ +1 Cl [ -1 Opposites attract

NH Cl = Ammonium Chloride 4 Another happy compound formed! [ +1 Cl [ -1 NH Cl = Ammonium Chloride 4 Another happy compound formed!

Practice Problem #4 Name the following compounds Ammonium sulfide Calcium sulfate Barium nitrate Potassium carbonate Magnesium phosphate Name the following compounds (NH4)2S CaSO4 Ba(NO3)2 K2CO3 Mg3(PO4)2

Practice Problem #5 Write formulas for the following compounds Aluminum nitrate Beryllium sulfate Calcium phosphite Ammonium sulfite Strontium nitrite Al(NO3)3 BeSO4 Ca3(PO3)2 (NH4)2SO3 Sr(NO2)2

Covalent Bonds Cl Cl Compounds formed by two non-metals More of a sharing of electrons rather than a give-take relationship Cl Cl

Can you spare an electron? Cl Cl

JINX! Cl Cl

Why don’t you share an electron? You know sharing is caring! Cl Cl

Valent=valence electrons… therefore, covalent is sharing electrons! Co=together Valent=valence electrons… therefore, covalent is sharing electrons! Shared pair of electrons = Covalent Bond Cl Cl

Naming Covalent Bonds Prefixes on back of periodic table If there is only one of the first element, no prefix. Otherwise attach prefix Second always gets prefix and -ide ending (just like ionic anion) Name these ICl5 N2O

Practice Problem #7 Name the following covalent compounds Carbon dioxide Phosphorous pentachloride Carbon monoxide Triphosphorous hexaflouride Name the following covalent compounds CO2 PCl5 CO P3F6

Practice Problem #8 Give the formula for the following compounds Sodium acetate Nickel (II) chloride Carbon dioxide Sulfur trioxide Triphosphorous tetrachloride NaC2H3O2 NiCl2 CO2 SO3 P3Cl4

One more thing… If the ionic compound begins with a hydrogen ion, it’s an acid We name binary acids by adding hydro as a prefix to the root of the anion and add ic, then add the word acid Name these: HCl HI HF HBr

Acids involving polyatomic anions These are even easier, They’ll always involve oxygen If an -ate ion, use root of polyatomic and add -ic If an -ite ion, use root of polyatomic and add -ous Then just add the word acid If I ATE it I would say IC!

Practice Problem #6 Write the formulas for these acids H2SO4 H2CO3 HNO3 HNO2 H3PO4 H3PO3 Write the formulas for these acids Sulfuric acid Sulfurous acid Carbonic acid Nitric acid Nitrous acid Phosphoric acid Phosphorous acid

THAT’S ALL FOLKS!