Writing Formulas Ionic Compounds with Polyatomic Ions

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.

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.

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. 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. 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”.

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 – charges 2.Crossing down charges

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges Formula

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – 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? Ni 3+

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – 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 Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges Formula

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges Formula Charge = –1

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges Formula NOT the Charge!

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges Formula Charge = –1

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges+3–1 Formula

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges+3–3 Formula

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges+3–3 Formula

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – 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 Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges+3–3 Formula Ni(ClO 3 ) 3

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges+3–3 Formula Ni(ClO 3 ) 3

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges+3–3 Formula Ni(ClO 3 ) 3

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges+3–3 Formula Ni(ClO 3 ) 3

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges+3–3 Formula Ni(ClO 3 ) 3

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges+3–3 Formula Ni(ClO 3 ) 3

Finding a formula by equalizing + and – charges What is the formula for nickel(III) chlorate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges+3–3 Formula Ni(ClO 3 ) 3

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 AgNO 3

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 AgNO 3

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 AgNO 3 ammonium chloride NH 4 Cl

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 AgNO 3 ammonium chloride NH 4 Cl

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 AgNO 3 ammonium chloride NH 4 Cl potassium hydrogen sulphite KHSO 3

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 AgNO 3 ammonium chloride NH 4 Cl potassium hydrogen sulphite KHSO 3

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(NO 3 ) 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(NO 3 ) 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(NO 3 ) 2 ammonium carbonate (NH 4 ) 2 CO 3

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(NO 3 ) 2 ammonium carbonate (NH 4 ) 2 CO 3

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(NO 3 ) 2 ammonium carbonate (NH 4 ) 2 CO 3

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(NO 3 ) 2 ammonium carbonate (NH 4 ) 2 CO 3 chromium(II) phosphate Cr 3 (PO 4 ) 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(NO 3 ) 2 ammonium carbonate (NH 4 ) 2 CO 3 chromium(II) phosphate Cr 3 (PO 4 ) 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(NO 3 ) 2 ammonium carbonate (NH 4 ) 2 CO 3 chromium(II) phosphate Cr 3 (PO 4 ) 2

Finding a formula by equalizing + and – charges What is the formula for tin(IV) chromate? Ion Namenickel(III)chlorate Ions Ni 3+ ClO 3 – Total Charges Formula

Finding a formula by equalizing + and – charges What is the formula for tin(IV) chromate? Ion Nametin(IV)chromate Ions Ni 3+ ClO 3 – Total Charges Formula

Finding a formula by equalizing + and – charges What is the formula for tin(IV) chromate? Sn 4+

Finding a formula by equalizing + and – charges What is the formula for tin(IV) chromate? Ion Nametin(IV)chromate Ions Sn 4+ CrO 4 2– 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 Nametin(IV)chromate Ions Sn 4+ CrO 4 2– Total Charges Formula

Finding a formula by equalizing + and – charges What is the formula for tin(IV) chromate? Ion Nametin(IV)chromate Ions Sn 4+ CrO 4 2– Total Charges+4–2 Formula

Finding a formula by equalizing + and – charges What is the formula for tin(IV) chromate? Ion Nametin(IV)chromate Ions Sn 4+ CrO 4 2– Total Charges+4–2 Formula

Finding a formula by equalizing + and – charges What is the formula for tin(IV) chromate? Ion Nametin(IV)chromate Ions Sn 4+ CrO 4 2– Total Charges+4–4 Formula

Finding a formula by equalizing + and – charges What is the formula for tin(IV) chromate? Ion Nametin(IV)chromate Ions Sn 4+ CrO 4 2– 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 Nametin(IV)chromate Ions Sn 4+ CrO 4 2– Total Charges+4–4 Formula Sn(CrO 4 ) 2

Finding a formula by crossing down charges What is the formula for ammonium phosphite? NH 4 + PO 3 3– (NH 4 ) 3 PO 3

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? NH 4 + PO 3 3– (NH 4 ) 3 PO 3

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? NH 4 + PO 3 3– (NH 4 ) 3 PO 3

Finding a formula by crossing down charges What is the formula for ammonium phosphite? NH 4 + PO 3 3– (NH 4 ) 3 PO 3

Finding a formula by crossing down charges What is the formula for ammonium phosphite? NH 4 + PO 3 3– (NH 4 ) 3 PO 3

Finding a formula by crossing down charges What is the formula for ammonium phosphite? NH 4 + PO 3 3– (NH 4 ) 3 PO 3

Finding a formula by crossing down charges What is the formula for ammonium phosphite? NH 4 + PO 3 3– (NH 4 ) 3 PO 3

Finding a formula by crossing down charges What is the formula for ammonium phosphite? NH 4 + PO 3 3– (NH 4 ) 3 PO 3

Finding a formula by crossing down charges What is the formula for ammonium phosphite? NH 4 + PO 3 3– (NH 4 ) 3 PO 3

Finding a formula by crossing down charges What is the formula for ammonium phosphite? NH 4 + PO 3 3– (NH 4 ) 3 PO 3 Formula