• There is a systematic process in the naming of inorganic acids. Probably the most significant problem is the variation of oxidation numbers for the negative ions.

• For example

Cl-1 chloride ion

NO3-1 nitrate ion

SO4-2 sulfate ion

PO4-3 phosphate

ion

• Another significant problem is that many of the other polyatomic ions with the same endings on their names have a different number of oxygen atoms attached to the central atom.

• For example

chlorate ClO3-1

sulfate SO4-2

phosphate PO4-3

acetate C2H3O2-1

» ClO4-1 perchlorate

» ClO3-1 chlorate

» ClO2-1 chlorite

» ClO-1 hypochlorite» Cl-1 chloride (not a polyatomic

ion)

» ClO4-1 perchlorate

» ClO3-1 chlorate

» ClO2-1 chlorite

» ClO-1 hypochlorite

» Cl-1 chloride

» ClO4-1 perchlorate

» ClO3-1 chlorate

» ClO2-1 chlorite

» ClO-1 hypochlorite

» Cl-1 chloride

» ClO4-1 perchlorate

» ClO3-1 chlorate

» ClO2-1 chlorite

» ClO-1 hypochlorite

» Cl-1 chloride

All the ions contain one chlorine atom but a varying number of oxygen atoms

All have a minus one charge

• Rather than memorize all the polyatomic

Ions it is much more useful to learn their trends in the naming scheme. There are numerous patterns within a homologous series.

• For example

All the names contain chlor indicating that the ion contains chlorine

The oxy-ions of chlorine, bromine and iodine all have these trends in common. Look for them below……

perchlorate ClO4-1

chlorate ClO3-1

chlorite ClO2-1

hypochlorite ClO-1

Perbromate BrO4-1

Bromate BrO3-1

Bromite BrO2-1

Hypobromite BrO-1

Periodate IO4-1

Iodate IO3-1

Iodite IO2-1

Hypoiodite IO-1

The most productive method of committing these ions to memory is first memorize the ones that have the _____ate ending. . This is the most common ending.

POLYATOMIC IONS

Ions with -1 chargeperbromate BrO4

-1

bromate BrO3-1

bromite BrO2-1

hypobromite BrO-1

perchlorate ClO4-1

chlorate ClO3-1

chlorite ClO2-1

hypochlorite ClO-1

periodate IO4-1

iodate IO3-1

iodite IO2-1

hypoiodite IO-1

nitrate NO3-1

nitrite NO2-1

hydroxide OH-1

cyanide CN-1

thiocyanate SCN-1

acetate C2H3O2-

1

permanganate MnO4-1

bicarbonate HCO3-1

Ions with a -2 Chargecarbonate CO3

-2

phthalate C8H4O4-

2

sulfate SO4-2

sulfite SO3-2

chromate CrO4-2

dichromate Cr2O7-2

oxalate C2O4-2

peroxide O2-2

Ions with a -3 Charge

phosphate PO4-3

phosphite PO3-3

arsenate AsO4-3

Ions with +1 chargeammonium ionNH4

+1

Salt metal polyatomic ion # Oxygen

atoms

________ per_____ate 4 ________ _____ate 3

________ _____ite 2

________ hypo_____ite 1

________ _____ide 0

The table below shows the prefixes and suffixes that tell the number of oxygen atoms present in the negative ion.

REMEMBER

the aqueous acid names are simply an extension of the salt names.

To transform the metal per____ate salt into its corresponding aqueous acid name:

1) The name of the metal is dropped 2) The -ate ending is replaced with –ic3) The word acid is added to the name

For example:

potassium perchlorate > perchloric acid KClO4(s) > HClO4 (aq)

Aqueous Acid hydrogen polyatomic ion

per_____ic acid

_____ic acid

_____ous acid

hypo______ous acid

hydro______ic acid

Salt metal polyatomic ion

________ per_____ate

________ _____ate

________ _____ite

________ hypo_____ite

________ _____ide

To transform the metal _____ate salt into its corresponding aqueous acid name:

1) The name of the metal is dropped 2) The -ate ending is replaced with –ic3) The word acid is added to the name

For example:

sodium acetate > acetic acid NaC2H3O2(s) > HC2H3O2(aq)

Salt metal polyatomic ion

________ per_____ate

________ _____ate

________ _____ite

________ hypo_____ite

________ _____ide

Aqueous Acid hydrogen polyatomic ion

per_____ic acid

_____ic acid

_____ous acid

hypo______ous acid

hydro______ic acid

Salt metal polyatomic ion

________ per_____ate

________ _____ate

________ _____ite

________ hypo_____ite

________ _____ide

Aqueous Acid hydrogen polyatomic ion

per_____ic acid

_____ic acid

_____ous acid

hypo______ous acid

hydro______ic acid

To transform the metal_____ite salt into its corresponding aqueous acid name:

1) The name of the metal is dropped 2) The -ite ending is replaced with –ous3) The word acid is added to the name

For example:

ammonium nitrite > nitrous acid NH4NO2(s) > HNO2(aq)

Salt metal polyatomic ion

________ per_____ate

________ _____ate

________ _____ite

________ hypo_____ite

________ _____ide

Aqueous Acid hydrogen polyatomic ion

per_____ic acid

_____ic acid

_____ous acid

hypo______ous acid

hydro______ic acid

To transform the metal hypo_____ite salt into its corresponding aqueous acid name:

1) The name of the metal is dropped 2) The -ite ending is replaced with –ous3) The word acid is added to the name

For example:

lithium hypoiodite > hypoiodous acid LiIO (s) > HIO (aq)

Salt metal polyatomic ion

________ per_____ate

________ _____ate

________ _____ite

________ hypo_____ite

________ _____ide

Aqueous Acid hydrogen polyatomic ion

per_____ic acid

_____ic acid

_____ous acid

hypo______ous acid

hydro______ic acid

To transform the metal _____ide salt into its corresponding aqueous acid name:

1) The name of the metal is dropped 2) The -ide ending is replaced with

hydro____ic3) The word acid is added to the name

For example:

silver bromide > hydrobromic acid AgBr(s) > HBr(aq)

The following exercises will deal only with the names and formulas of aqueous acids. The names and formulas for the salts were studied in detail in a previous lesson.

Example #1-Names to Formulas

HClO3

2. Add hydrogen ions

1. Determine the formula & charge of the polyatomic ion

Final Formula

chloric acid

(aq)

chlorate

-1+1

3. Balance charge with ions

4. Add the subscript: (aq)

=0

Examples #1- Formulas to Names

2. Determine the ion and it’s acid ending.

1. The hydrogen out front & the (aq) subscript indicates an acid

Final Name

HBrO2(aq)

bromous acid

bromite

____________ acid

Examples #10- Formulas to Names

2. Determine the ion and it’s acid ending.

1. The hydrogen out front & the (aq) subscript indicates an acid

Final Name

HBrO2(aq)

bromous acid

bromite

____________ acid

Practice Problem #1HIO4(aq)

Choose the correct name for the compound

1. iodic acid

2. iodous acid

3. periodic acid

4. hydrogen periodate

5. none of the abovenext

problemIon list

Practice Problem #2hydrobromic acid

Choose the correct formula for the compound

1. HBrO(aq)

2. HBr(aq)

3. HBrO3(aq)

4. HBrO2(aq)

5. none of the above

next problem

Ion list

POLYATOMIC IONS

Ions with -1 chargeperbromate BrO4

-1

bromate BrO3-1

bromite BrO2-1

hypobromite BrO-1

perchlorate ClO4-1

chlorate ClO3-1

chlorite ClO2-1

hypochlorite ClO-1

periodate IO4-1

iodate IO3-1

iodite IO2-1

hypoiodite IO-1

nitrate NO3-1

nitrite NO2-1

hydroxide OH-1

cyanide CN-1

thiocyanate SCN-1

acetate C2H3O2-

1

permanganate MnO4-1

bicarbonate HCO3-1

Ions with a -2 Chargecarbonate CO3

-2

phthalate C8H4O4-

2

sulfate SO4-2

sulfite SO3-2

chromate CrO4-2

dichromate Cr2O7-2

oxalate C2O4-2

peroxide O2-2

Ions with a -3 Charge

phosphate PO4-3

phosphite PO3-3

arsenate AsO4-3

Ions with +1 chargeammonium ionNH4

+1

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