Summary

Writing and Naming Compounds

Given an English name, write a chemical formula: Binary Ionic

compounds (2 elements)• Ex:

sodium chloride, iron (II) sulfide, aluminum oxide

• Step 1– Write the formula for the ion (if it ends in –ide it is on the periodic table!!)

• Na+ Cl-

•Step 2•Balance Charges (Crisscross—be careful)•Use subscripts to indicate how many of the element you need

Fe+2 S-2 Al+3 O-2

Things to Remember

• NEVER write charges in a compound!

• Elements that show a roman numeral—the roman numeral IS THE CHARGE!

• If the name of the ANION (the negative or second thing written) ends in –ide it is an element off of the periodic table!

NaCl FeS Al2O3

Given an English name, write a chemical formula: Ternary Ionic

compounds (more than2 elements)• Ex

lithium hydroxide**, zinc nitrate, aluminum sulfate

• Step 1– Write the formula for the ion (if it ends in –ate or ite it is a

polyatomic ion! ** Hydroxide and cyanide are the exception to that rule!)

Li+ OH- Zn+2 NO3- Al+3 SO4

-2

• Step 2Balance Charges (Crisscross—be careful)Use subscripts to indicate how many of the element you need

Things to Remember

• If you need more than one polyatomic ion (if cation charge is more than one you will)

• USE PARENTHESIS!

• LiOH no parenthesis

• Zn(NO3)2 parenthesis were needed

• Al2(SO4)3 parenthesis were needed

Given a Chemical Formula-Write the English Name-Binary Ionics

STEP 1—Naming the Metal– Look up the metal on the periodic table– Write the name of the metal– Decide if the metal needs a ROMAN NUMERAL– If the metal has more than ONE CHOICE for a

charge it needs a ROMAN NUMERAL.– Use the charge on the ANION to calculate the

charge of the CATION! (Don’t un-crisscross!)

Ex:CaCl2 CuO ZnBr2 NiF2

• Step 2—Naming the ANION

• If the ANION IS A SINGLE ELEMENT change the ending to --ide

Calcium Chloride

Copper (II) oxide

Zinc Bromide

Nickel (II) Flouride

Given a Chemical Formula-Write the English Name-Ternary Ionics

3 or more elements!

• Step 1—Naming the CATION (Metal)– Use the same rules for naming the CATION

•Step 2—Naming the polyatomic ion •If the name given ends in ate or ite** DO NOT CHANGE THE NAME—You either know it or it is on your list!

Ex:Bi3(PO4)5 Mn(NO3)7 CdCO3

• Bismuth (V) phosphate

• Manganese (VII) nitrate (it doesn’t matter if that choice is not on the table put whatever you calculate to be the charge as the roman numeral!!! All of the charges are not shown on your PT.

• Cadmium (II) carbonate