Writing Formulas Ionic Compounds with Polyatomic

Ions

A polyatomic ion is an ion that contains more than one atom.

A polyatomic ion is an ion that contains more than one atom.It is a group of atoms which acts as a single unit and has its own unique charge.

A polyatomic ion is an ion that contains more than one atom.It is a group of atoms which acts as a single unit and has its own unique charge. An example of a polyatomic ion is the nitrate ion

A polyatomic ion is an ion that contains more than one atom.It is a group of atoms which acts as a single unit which has its own charge. An example of a polyatomic ion is the nitrate ion . 3NO

A polyatomic ion is an ion that contains more than one atom.It is a group of atoms which acts as a single unit which has its own charge. An example of a polyatomic ion is the nitrate ion . 3NO

A polyatomic ion is an ion that contains more than one atom.It is a group of atoms which acts as a single unit which has its own charge. An example of a polyatomic ion is the nitrate ion . 3NO

N

O

OO

–

A table provided in Science 10 gives the names, formulas, and charges of many common polyatomic ions.Ion Table

A table provided in Science 10 gives the names, formulas, and charges of many common polyatomic ions.Ion Table

A table provided in Science 10 gives the names, formulas, and charges of many common polyatomic ions.Ion Table

Notice the endings of the names of polyatomic ions. Many end in “ATE”, some end in “ITE” and a few end in “IDE”

There are a few polyatomic ions that have more than one possible name.

There are a few polyatomic ions that have more than one possible name.

There are a few polyatomic ions that have more than one possible name. For example hydrogen carbonate,can also be called bicarbonate. Be aware that the “bi” prefix in these ions does NOT mean “2”. It actually stands for “hydrogen”.

3HCO

There are two methods that we will show you for finding formulas of compounds with polyatomic ions. They are:

There are two methods that we will show you for finding formulas of compounds with polyatomic ions. They are:

1. Equalizing + and – charges

There are two methods that we will show you for finding formulas of compounds with polyatomic ions. They are:

1. Equalizing + and – charges2. Crossing down charges

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges

Formula

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges

Formula

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ni3+

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges

Formula

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges

Formula

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges

Formula

Charge = –1

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges

Formula

NOT the Charge!

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges

Formula

Charge = –1

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges +3 –1

Formula

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges +3 –3

Formula

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges +3 –3

Formula

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges +3 –3

Formula

Add up to 0

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges +3 –3

Formula Ni(ClO3)3

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges +3 –3

Formula Ni(ClO3)3

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges +3 –3

Formula Ni(ClO3)3

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges +3 –3

Formula Ni(ClO3)3

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges +3 –3

Formula Ni(ClO3)3

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges +3 –3

Formula Ni(ClO3)3

Finding a formula by equalizing + and – charges

What is the formula for nickel(III) chlorate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

ClO3–

Total Charges +3 –3

Formula Ni(ClO3)3

Just a note here about brackets.

Just a note here about brackets.If there is only one unit of a particular polyatomic ion in a compound, brackets are not needed, and should not be included.

Just a note here about brackets.If there is only one unit of a particular polyatomic ion in a compound, brackets are not needed, and should not be included. Examples are:

Just a note here about brackets.If there is only one unit of a particular polyatomic ion in a compound, brackets are not needed, and should not be included. Examples are: silver nitrate AgNO3

Just a note here about brackets.If there is only one unit of a particular polyatomic ion in a compound, brackets are not needed, and should not be included. Examples are: silver nitrate AgNO3

Just a note here about brackets.If there is only one unit of a particular polyatomic ion in a compound, brackets are not needed, and should not be included. Examples are: silver nitrate AgNO3

ammonium chloride NH4Cl

Just a note here about brackets.If there is only one unit of a particular polyatomic ion in a compound, brackets are not needed, and should not be included. Examples are: silver nitrate AgNO3

ammonium chloride NH4Cl

Just a note here about brackets.If there is only one unit of a particular polyatomic ion in a compound, brackets are not needed, and should not be included. Examples are: silver nitrate AgNO3

ammonium chloride NH4Clpotassium hydrogen sulphite KHSO3

Just a note here about brackets.If there is only one unit of a particular polyatomic ion in a compound, brackets are not needed, and should not be included. Examples are: silver nitrate AgNO3

ammonium chloride NH4Clpotassium hydrogen sulphite KHSO3

If there is more than one unit of a particular polyatomic ion in a compound, brackets are needed, and must be included. Examples are:

If there is more than one unit of a particular polyatomic ion in a compound, brackets are needed, and must be included. Examples are:copper(II) nitrate Cu(NO3)2

If there is more than one unit of a particular polyatomic ion in a compound, brackets are needed, and must be included. Examples are:copper(II) nitrate Cu(NO3)2

If there is more than one unit of a particular polyatomic ion in a compound, brackets are needed, and must be included. Examples are:copper(II) nitrate Cu(NO3)2 ammonium carbonate (NH4)2CO3

If there is more than one unit of a particular polyatomic ion in a compound, brackets are needed, and must be included. Examples are:copper(II) nitrate Cu(NO3)2 ammonium carbonate (NH4)2CO3

If there is more than one unit of a particular polyatomic ion in a compound, brackets are needed, and must be included. Examples are:copper(II) nitrate Cu(NO3)2 ammonium carbonate (NH4)2CO3

If there is more than one unit of a particular polyatomic ion in a compound, brackets are needed, and must be included. Examples are:copper(II) nitrate Cu(NO3)2 ammonium carbonate (NH4)2CO3

chromium(II) phosphate Cr3(PO4)2

If there is more than one unit of a particular polyatomic ion in a compound, brackets are needed, and must be included. Examples are:copper(II) nitrate Cu(NO3)2 ammonium carbonate (NH4)2CO3

chromium(II) phosphate Cr3(PO4)2

If there is more than one unit of a particular polyatomic ion in a compound, brackets are needed, and must be included. Examples are:copper(II) nitrate Cu(NO3)2 ammonium carbonate (NH4)2CO3

chromium(II) phosphate Cr3(PO4)2

Finding a formula by equalizing + and – charges

What is the formula for tin(IV) chromate?

Ion Name nickel(III) chlorate

Ions Ni3+ ClO3–

ClO3–

Total Charges

Formula

Finding a formula by equalizing + and – charges

What is the formula for tin(IV) chromate?

Ion Name tin(IV) chromate

Ions Ni3+ ClO3–

ClO3–

Total Charges

Formula

Finding a formula by equalizing + and – charges

What is the formula for tin(IV) chromate?

Sn4+

Finding a formula by equalizing + and – charges

What is the formula for tin(IV) chromate?

Ion Name tin(IV) chromate

Ions Sn4+ CrO42–

CrO42–

Total Charges

Formula

Finding a formula by equalizing + and – charges

What is the formula for tin(IV) chromate?

Finding a formula by equalizing + and – charges

What is the formula for tin(IV) chromate?

Ion Name tin(IV) chromate

Ions Sn4+ CrO42–

CrO42–

Total Charges

Formula

Finding a formula by equalizing + and – charges

What is the formula for tin(IV) chromate?

Ion Name tin(IV) chromate

Ions Sn4+ CrO42–

CrO42–

Total Charges +4 –2

Formula

Finding a formula by equalizing + and – charges

What is the formula for tin(IV) chromate?

Ion Name tin(IV) chromate

Ions Sn4+ CrO42–

CrO42–

Total Charges +4 –2

Formula

Finding a formula by equalizing + and – charges

What is the formula for tin(IV) chromate?

Ion Name tin(IV) chromate

Ions Sn4+ CrO42–

CrO42–

Total Charges +4 –4

Formula

Finding a formula by equalizing + and – charges

What is the formula for tin(IV) chromate?

Ion Name tin(IV) chromate

Ions Sn4+ CrO42–

CrO42–

Total Charges +4 –4

Formula

Add up to 0

Finding a formula by equalizing + and – charges

What is the formula for tin(IV) chromate?

Ion Name tin(IV) chromate

Ions Sn4+ CrO42–

CrO42–

Total Charges +4 –4

Formula Sn(CrO4)2

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

NH4+ PO3

3–

(NH4)3PO3

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

NH4+ PO3

3–

(NH4)3PO3

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

NH4+ PO3

3–

(NH4)3PO3

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

NH4+ PO3

3–

(NH4)3PO3

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

NH4+ PO3

3–

(NH4)3PO3

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

NH4+ PO3

3–

(NH4)3PO3

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

NH4+ PO3

3–

(NH4)3PO3

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

NH4+ PO3

3–

(NH4)3PO3

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

NH4+ PO3

3–

(NH4)3PO3

Finding a formula by crossing down charges

What is the formula for ammonium phosphite?

NH4+ PO3

3–

(NH4)3PO3Formula