Naming/Formula Writing for Ionic Compounds 1. Name the cation (+ ion) first 2. Name the anion (- ion) next, but change the ending to “ide”.

Name: CaO K 2 S Na 3 N

Calcium oxide Potassium sulfide Sodium nitride

When writing formulas, the cation’s atomic symbol (capitals and small letters ARE IMPORTANT) is followed by the anion’s atomic symbol.

The compound must have a zero (neutral) total charge. The subscript(s) tells the number of each anion and cation it takes to make it neutral. No subscript is used if there is only one.

Write the formulas for: Calcium bromide Potassium sulfide Magnesium nitride

CaBr 2 K 2 S Mg 3 N 2

Warm up: 1)Name 3 properties of ionic compounds. 2)Write the formula and name the compound that will be formed from Barium and Iodine.

1)Name 3 properties of ionic compounds. Dissolve in water, metals and nonmetals combined, high electronegativity difference, crystalline solids 2) Write the formula and name the compound that will be formed from Barium and Iodine. BaI 2 Barium Iodide

Polyatomic ions Sometimes atoms covalently (more later) bond to produce an ion composed of several different atoms. Called polyatomic ions. Indicated by: More than 2 elements in a compound Parentheses Listed on back of your periodic table.

When there is more than one polyatomic ion in a formula it must be offset with parenthesis before putting in the subscript.

Write the formula for: Potassium phosphate Aluminum dichromate Ammonium sulfide

Write the formula for: Potassium phosphate K 3 PO 4 Aluminum dichromate Al 2 (Cr 2 O 7 ) 3 Ammonium sulfide (NH 4 ) 2 S

NH 4 + combined with PO 4 3- Fe 3+ combined with CO 3 2-

Write the formula for: NH 4 + combined with PO 4 3- (NH 4 ) 3 PO 4 Fe 3+ combined with CO 3 2- Fe 2 (CO 3 ) 3

Naming with Transition metals Transition metals (B group, d orbitals), Tin, and Lead can often take on several different (+) charges. You can know charge in formula by looking at what it’s bonded to. You can know charge in name by a roman numeral. Common ones on back of periodic table

Practice What is the charge of the Pb in PbS 2 ? What is its name?

Practice What is the charge of the Pb in PbS 2 ? What is its name? 4 Lead (IV) sulfide

What is the charge of the Ni in NiCl 2 ? What is its name?

2 Nickel (II) chloride

What is the charge of the Mn in MnBr 4 ? What is its name?

4 Manganese (IV) bromide

What is the charge of the Mn in Manganese (IV) Oxide? What is its formula?

What is the charge of the Mn in Manganese (IV) Oxide? What is its formula? 4 MnO 2

What is the charge of the Co in Cobalt (III) Chloride? What is its formula?

What is the charge of the Co in Cobalt (III) Chloride? What is its formula? 3 CoCl 3

What is the charge of the Pb in Lead (II) Bicarbonate? What is its formula?

What is the charge of the Pb in Lead (II) Bicarbonate? What is its formula? 2 Pb(HCO 3 ) 2

Ions in lab Generally ions are soluble in water.

When they are dissolved they are free to bounce into other ions. Sometimes the new compound they make isn’t soluble in water.

This compound will fall out as a precipitate. Precipitates are solids that come out of the solution. They are opaque and come in different colors.