Names and Formulas for Ionic Compounds

Do Now:Article: 222, 226 Mastering Concepts: 236(54-56) Terms: 221 Practice Problems: 224(19-23) 225(24-28)226(29-33)

Homework: Cornell Notes: 8.3 Section Assessment: 227(34-38) 9 Stamps

Section 8-3Section 8.3 Names and Formulas for Ionic Compounds

• Relate a formula unit of an ionic compound to its composition.

nonmetal: an element that is generally a gas or a dull, brittle solid and is a poor conductor of heat and electricity

• Write formulas for ionic compounds and oxyanions.

• Apply naming conventions to ionic compounds and oxyanions.

Section 8-3Section 8.3 Names and Formulas for Ionic Compounds (cont.)

formula unitmonatomic ionoxidation numberpolyatomic ionoxyanion

In written names and formulas for ionic compounds, the cation appears first, followed by the anion.

Section 8-3Formulas for Ionic Compounds

• When writing names and formulas for ionic compounds, the cation appears first followed by the anion.

• Chemists around the world need to communicate with one another, so a standardized system of naming compounds was developed.

Section 8-3Formulas for Ionic Compounds (cont.)

• A formula unit represents the simplest ratio of the ions involved.

• Monatomic ions are one-atom ions.

Section 8-3Formulas for Ionic Compounds (cont.)

• Oxidation number, or oxidation state, is the charge of a monatomic ion.

Section 8-3Formulas for Ionic Compounds (cont.)

• The symbol for the cation is always written first, followed by the symbol of the anion.

• Subscripts represent the number of ions of each element in an ionic compound.

• The total charge must equal zero in an ionic compound.

Section 8-3Formulas for Ionic Compounds (cont.)

• Polyatomic ions are ions made up of more than one atom.

• Never change subscripts of polyatomic ions, place in parentheses and write the appropriate subscript outside the parentheses.

Section 8-3Formulas for Ionic Compounds (cont.)

Section 8-3Names for Ions and Ionic Compounds

• An oxyanion is a polyatomic ion composed of an element (usually a non-metal), bonded to one or more oxygen atoms.

Section 8-3Names for Ions and Ionic Compounds (cont.)

Section 8-3Names for Ions and Ionic Compounds (cont.)

• Chemical nomenclature is a systematic way of naming compounds.

– Name the cation followed by the anion.– For monatomic, cations use the element name.– For monatomic anions, use the root element

name and the suffix –ide.

– To distinguish between different oxidation states of the same element, the oxidation state is written in parentheses after the name of the cation.

– When the compound contains a polyatomic ion, name the cation followed by the name of the polyatomic ion.

Section 8-3Names for Ions and Ionic Compounds (cont.)

Practice Problems: 224 (19-23)

Write the correct formula for the ionic compound composed of the following pairs of ions.

19. Potassium and iodide20. Magnesium and chloride21. Aluminum and bromide22. Cesium and nitride23. Barium and sulfide

15

Practice Problems: 224 (19-23)

Write the correct formula for the ionic compound composed of the following pairs of ions.

19. Potassium and iodide

16

K+ I-

KI

Practice Problems: 224 (19-23)

Write the correct formula for the ionic compound composed of the following pairs of ions.

20. Magnesium and chloride

17

Mg+2 Cl-

MgCl2

Practice Problems: 224 (19-23)

Write the correct formula for the ionic compound composed of the following pairs of ions.

21. Aluminum and bromide

18

Al+3 Br-

AlBr3

Practice Problems: 224 (19-23)

Write the correct formula for the ionic compound composed of the following pairs of ions.

22. Cesium and nitride

19

Cs+1 N-3

Cs3N

Practice Problems: 224 (19-23)

Write the correct formula for the ionic compound composed of the following pairs of ions.

23. Barium and sulfide

20

Ba+2 S-2

Ba2S2 Simplest formula

BaS

Section 8-3Formulas for Ionic Compounds (cont.)

Copy p.224

Practice Problems: 225 (24-28)Determine the correct formula for the ionic

compound composed of the following pairs of ions.

24. Sodium and nitrate25. Calcium and chlorate26. Aluminum and carbonate27. Potassium and chromate28.Magnesium and carbonate

22

Write the correct formula for the ionic compound composed of the following pairs of ions.

24. Sodium and nitrate

23

Na+ NO3-

NaNO3

Practice Problems: 225 (24-28)

Write the correct formula for the ionic compound composed of the following pairs of ions.

25. Calcium and chlorate

24

Ca+2 ClO3-

Ca(ClO3)2

Practice Problems: 225 (24-28)

Write the correct formula for the ionic compound composed of the following pairs of ions.

26. Aluminum and carbonate

25

Al+3 CO3-2

Al2(CO3)3

Practice Problems: 225 (24-28)

Write the correct formula for the ionic compound composed of the following pairs of ions.

27. Potassium and chromate

26

K+ CrO4-2

K2CrO4

Practice Problems: 225 (24-28)

Write the correct formula for the ionic compound composed of the following pairs of ions.

28.Magnesium and carbonate

27

Mg+2 CO3-2

Mg2(CO3)2

Practice Problems: 225 (24-28)

Simplest formula

MgCO3

Metal

Has fewer electrons

Lose electrons +

Non Metal

Has more electrons

Gain electrons -

Formation of Ionic Bond

Naming of Ionic Bond

Cation Anion

Practice Problems: 226 (29-33)

Name the following compounds.29. NaBr30. CaCl2

31. KOH32. Cu(NO3)2

33. Ag2CrO4

29

Metal Non MetalNaming of Ionic Bond

Cation Anion -ide

29. NaBrSodium Brom

Sodium Bromideine-ide

Metal Non MetalNaming of Ionic Bond

Cation Anion -ide

30. CaCl2

Calcium ChlorCalcium Chloride

ine-ide

Naming of Ionic Bond

Cation Polyatomic ion

31. KOHPotassium Hydroxide

Potassium Hydroxide

Naming of Ionic Bond

Cation Polyatomic ion

32. Cu(NO3)2

Copper NitrateCopper II Nitrate

II

Transition Metal requires roman numerals

Naming of Ionic Bond

Cation Polyatomic ion

33. Ag2CrO4

Silver ChromateSilver Chromate