Nomenclature (aka naming)

Why name a compound?Well, for one thing, so you don’t end up with a recipe like this:

Ingredients:

1. 532.35 cm3 gluten2. 4.9 cm3 NaHCO3

3. 4.9 cm3 refined halite4. 236.6 cm3 partially hydrogenated tallow triglyceride5. 177.45 cm3 crystalline C12H22O11

6. 177.45 cm3 unrefined C12H22O11

7. 4.9 cm3 methyl ether of protocatechuic aldehyde8. Two calcium carbonate-encapsulated avain albumen-coated protein9. 473.2 cm3 theobroma cacao10. 236.6 cm3 de-encapsulated legume meats (sieve size #10)

Why name a compound?What are you putting on your head, anyway?

Polyatomic IonsPolyatomic ion: a group of atoms all covalently bonded together that have an overall charge.

Example: carbonate = CO3

2-

This is NOT a +4 carbon and three -2 oxygens; they are bonded into one group, move together as a group, and frequently react together as a group.

Structure:

C

O

OO – –

Polyatomic IonsCommon polyatomic ions (memorize these, including charge):

Chlorate: ClO3

-

Hydroxide: OH-

Nitrate: NO3

-

Carbonate: CO3

2-

Sulfate: SO4

2-

Phosphate: PO4

3-

Ammonium: NH4

+

How to Name a Compound1. Write down the name of the first element.2. Leave some space, and write down the name of the

second element, changing the ending to “-ide”.

(if either the first or second thing is a polyatomic ion instead of a single element, use the name of the group instead)

Examples: H2S hydrogen sulfide

Na2SO4 sodium sulfate

NH4Cl ammonium chloride

FeCl2 iron chloride

How to Name a CompoundMost important question:

Is it IONIC?

(again, the compound type, not the Greek pillar)

NO Will be adding prefixes to name

YES May be adding charge to name

Covalent CompoundsAdd prefixes that say how many of each element there are:

1 = mono 2 = di 3= tri 4 = tetra

5= penta 6 = hexa 7 = hepta 8 = octa

9 = nona 10 = deca

Two exceptions: *The last vowel of the prefix is dropped if it sounds funny with the beginning of the element name.* If the first element would be “mono”, the prefix is dropped.

H2S dihydrogen monosulfideCO2 carbon dioxideP2O5 diphophorous tetroxide

Ionic CompoundsQuestion number 2:

Is the metal one of the ones with a predictable charge?

YES you’re done

Na2SO4 sodium sulfate

AlCl3 aluminum chlorideMgO magnesium oxide

NO Add the charge of the metal in roman numerals after the metal name.

FeCl2 iron(II) chlorideSnO2 tin(IV) oxideAg2SO4 silver(I) sulfate

Why Add the Charge?Based on charge, there is only one combination of sodium and oxygen:

Na2O = sodium oxide

But iron can have different charges:

FeCl2 = iron chloride

FeCl3 = also iron chloride?

So there's no need to clarify forsodium, but there is for iron.

All Together Now

1. Is it ionic ?

Yes No

Add prefixes.2. Does the metal have a predictable charge?

You're done! Use formula to work out charge on each metal atom.Add charge in parentheses after metal name, usingRoman numerals.

Name of first element name of second element (ending with -ide)*

YesNo

ExamplesNa

2S = sodium sulfide

Na2SO

4 = sodium sulfate

Al2O

3 = aluminum oxide

C2H

6 = dicarbon hexahydride

C3H

8 = tricarbon octahydride

P2O

5 = diphosphorous pentoxide

FeCO3 = iron(II) carbonate

CuS = copper(II) sulfide

Cu2S = copper(I) sulfide

Cu2SO

4 = copper(I) sulfate