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Ionic Bonding and Naming

Chapter 7 and 9

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• SC1 Students will analyze the nature of matter and its classifications.

• SC1.b. Identify substances based on chemical and physical properties.

• SC1.c. Predict formulas for stable ionic compounds (binary and tertiary) based on balance of charges.

• SC1.d. Use IUPAC nomenclature for both chemical names and formulas:

• SC1.d.1 Ionic compounds (Binary and tertiary) • SC1.d.3 Acidic compounds (Binary and tertiary) • SC3.e. Compare and contrast types of chemical bonds (i.e.

ionic, covalent). • SC3.b. Use the orbital configuration of neutral atoms to explain

its effect on the atom’s chemical properties.

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What do we already know?• Protons determine the IDENTINTY of the element• Valance Electrons determine the CHEMICAL

properties of an element.• Valance electrons are the electrons in the OUTER

ENERGY level• For representative elements look at the group

number to determine the number of valance electrons

• Elements lose or gain electrons to achieve a full outer energy level (full OCTET)– Metals form CATIONS by losing electrons– Nonmetals form ANIONS by gaining electrons

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The Octet Rule• Octet rule stated that in forming compounds

atoms tend to achieve the electron configuration of a noble gas.

• An octet is a set of eight electrons• Atoms of metals tend to lose their valence

electrons leaving a complete octet in the next-lowest energy level.

• Atoms of some nonmetals tend to gain electrons or to share electrons with another nonmetals to achieve a complete octet.

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Lewis Structure • Electron dot structures (Lewis dot structure) are

diagram that show the valence electrons at dots.• Each valance electron is represented with a dot• Put one dot on each side of the symbol before

putting two on one side.• Examples

1.Carbon2.Calcium3.Chlorine4.Argon

4 valance e-2 valance e-7 valance e-8 valance e-

CCa

ClAr

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Formation of Ionic Compounds• Ionic compounds are compounds composed of

cations and anions.• Although they are compounds of ions, ionic

compounds are electrically neutral.– Ionic bonds are the electrostatic forces that hold ions

together in ionic compounds. They occur due to the transfer of electrons

– Chemical formula shows the kinds and numbers of atoms in the smallest representative unit of a substance.

– Formula unit is the lowest whole-number ratio of ions in an ionic compound

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Formula Writing1. When writing formulas the MOST METALIC

element is written first– Ionic bonds occur between METALS and NONMETALS

so the metal is ALWAYS written FIRST.2. Determine the ion that the elements will form3. Balance charges– Can switch charges and reduce if necessary– Or can use the following equation: # of metal x charge of metal + # of nonmetal x charge of nonmetal = 0 atoms atoms

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Formula Writing• Practice 1: Oxygen and Sodium

1. Sodium is metal so it MUST be written first2. Na forms +1 ion and O forms -2 ion3. Na+1 O-2 switching charges gives Na2O(# metal) +1 +(#nonmetal) -2 = 0 solve (2) +1 +(1) -2 = 0 gives Na2ONOTE: The subscript of 1 is NOT written

• Practice 2: Nitrogen and Aluminum1. Aluminum is metal so it MUST be written first2. Al forms +3 ion and N forms -3 ion3. Al+3 N-3 switching charges gives AlN (must reduce)(# metal) +3 +(#nonmetal) -3 = 0 solve (1) +3 +(1) -3 = 0 gives AlN

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Formula Writing• Practice 3: Calcium and Carbon

1. Calcium is metal so it MUST be written first2. Ca forms +2 ion and C forms -4 ion3. Ca+2 C-4 switching charges gives Ca2C(# metal) +2 +(#nonmetal) -4 = 0 solve (2) +2 +(1) -4 = 0 gives Ca2C

• Practice 4: Barium and Phosphate (PO4-3)

1. Barium is metal so it MUST be written first2. Ba forms +2 ion and PO4 is a -3 ion3. Al+2 PO4

-3 switching charges gives Al3(PO4)2 (# metal) +2 +(#nonmetal) -3 = 0 solve (3) +2 +(2) -3 = 0 gives Al3(PO4)2 MUST USE parenthesis to show having 2 phosphate molecules.

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Ionic Naming – Type 1 metalsType 1 metals are metals that form only 1 oxidation state.They are found in groups 1, 2, & 13 in addition to Zn+2, Cd+2, and Ag+1

1. Determine the Cation and the Anion2. If the cation is from a representative element write its

name3. The anion is a:

a. Polyatomic ion write it’s special nameb. Single nonmetal element write its root name followed by

“ide”4. write both parts of name side by side

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Ionic Naming – Type 1• Example 1: Ca3N2

1. Calcium is the cation, nitrogen is anion2. Calcium stays calcium3. Nitrogen is NOT a polyatomic so it becomes Nitride4. Ca3N2 is called calcium nitride

• Example 1: Ca3(PO4)2

1. Calcium is the cation, phosphate is anion2. Calcium stays calcium3. Phosphate is a polyatomic so it’s name is phosphate4. Ca3(PO4)2 is called calcium phosphate

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Ionic Naming – Type 1• Practice1. KCl2. AlCl3

3. Ca2C4. InN5. Rb3PO3

6. Al(OH)3

7. In2(SO3)3

8. (NH4)3Br

• Practice1. Potassium chloride2. Aluminum chloride3. Calcium carbide4. Indium nitride5. Rubidium phosphite6. Aluminum hydroxide7. Indium sulfite8. ** Ammonium bromide

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Ionic Naming – Type 2 metals• Most transition metals have the ability to borrow electrons

from other orbitals and can form ions with different charges.• Metals in group 14 also have multiple oxidation states. +2 or

+4• Example: Iron can from a +3 or +4 cation, copper can

from a +2 or +1 ion• Not ALL transition metal do this but MOST do so when we

name the compound we have to state the charge of the metal ion

• EXCEPTIONS: three transition metals that you MUST memorize the following: Zn+2, Cd+2, Ag+1 as they do NOT need roman numerals

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Ionic Naming – Type 2 Metals1. Determine the Cation and the Anion2. If the cation is from a transition element write its

name followed by a roman numeral to show the charge of the metal ion.

3. The anion is a: a. Polyatomic ion write it’s special nameb. Single nonmetal element write its root name

followed by “ide”4. write both parts of name side by side

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Ionic Naming – Type 2• Common Roman numerals you MUST

KNOW1. I 6. VI **2. II 7. VII3. III 8. VIII4. IV ** 9. IX5. V 10. X

** commonly confused by students

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Ionic Naming – Type 2• Example 1: FeO

1. Fe is cation and O is anion2. since Oxygen has a -2 charge Fe MUST have a +2 so it is

Iron (II)3. O is NOT a polyatomic so it becomes Oxide4. FeO is Iron (II) Oxide

• Example 2: Fe2O3

1. Fe is cation and O is anion2. since Oxygen has a -2 charge Fe MUST have a +3 so it is

Iron (III)3. O is NOT a polyatomic so it becomes Oxide4. FeO is Iron (III) Oxide

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Ionic Naming – Type 2• Example 3: FePO4

1. Fe is cation and PO4 is anion2. since PO4 has a -3 charge Fe MUST have a +3 so it is Iron (III)3. PO4 is a polyatomic so it is phosphate4. FeO is Iron (III) Phosphate

• Example 4: Ag2O1. Ag is cation and O is anion2. Ag is an exception and only forms a +1 ion so is Silver3. O is NOT a polyatomic so it becomes Oxide4. Ag2O is Sliver OxideRemember Zn+2, Cd+2, Ag+1 do NOT need roman numerals

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Ionic Names to formula1. Use the name to determine the ions of the

elements (or polyatomic) in compound2. Write the ions for each element3. Balance charges using either method(reduce if

necessary)– Chemical formulas for COMPOUNDS do NOT have

charges!!– The number of atoms MUST be shown as a subscript.– REMEMBER the size and the shape of the letters

matter when writing chemical formulas: COS and CoS are two different things

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Ionic Names to Formulas• Examples1. Strontium Sulfide• Sr+2 S-2 • SrS

2. Magnesium Cyanide• Mg +2 CN-1

• Mg(CN)2

3. Potassium Phosphide• K+1 P+3

• K3P

• Examples4. Zinc Oxide• Zn+1 O-2• Zn2O

5. Cobalt (II) Oxide• Co+2 O-2• CoO

6. Manganese (IV) Sulfate• Mn+4 S-2• MnS2

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Formation of Ionic Compounds• Metals lose their electrons to nonmetals• The opposite charges attract and form an ionic

bondNa + Cl →Na + Cl →Na+1 + Cl-1 → NaCl name is: sodium chloride

Mg + S →Mg + S →Mg+2 + S-2 → MgS name is: Magnesium Sulfide

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Properties of Ionic Compounds• Ionic compounds form by the TRANSFER of electrons• Most ionic compounds are crystalline solids at room

temperature.• Ions in the crystals are arranged in repeating three-

dimensional patterns.• The large attractive forces result in very stable structures• Ionic compounds generally have high melting points.• Ionic compounds can conduct an electric current when

melted or dissolved in water• The ion movement allows electricity to flow between

electrodes

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Metallic Bonds and Metallic Properties• The valence electrons of metal atoms can be modeled as

a sea of electrons.• Metallic bonds consist of the attraction of the free-

floating valence electrons for the positively charged metal ions.

• the sea-of-electrons models explains many physical properties of metals

• metals are good conductors of electric current because electrons can flow freely in them

• metals are malleable (can be hammered or forced into shapes.)

• metals are ductile (can be drawn into wires)

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Alloys• metal atoms are arranged in very compact and

orderly patterns• alloys are mixtures composed of two or more

elements, at least of one which is metal• alloys are important because their properties

are superior to those of their components elements.

• Bronze alloy is made of copper and iron• Steel alloys are made of iron and carbon with

additional elements.