Chapter 7

REALLY Important!!!

7.1 – Ionic Compounds: Ions for s and p block elements:

Group 1 Group 2 Group13 Group 14 Group 15 Group 16 Group 17H Be B C N O FLi Mg Al Si P S ClNa Ca Ga Ge BrK Sr In IRb Ba Tl AtCs RaFr

________ Valence e- ________ Valence e- ________ Valence e- ________ Valence e- ________ Valence e- ________ Valence e- ________ Valence e-

Dot Diag: Dot Diag: Dot Diag: Dot Diag: Dot Diag: Dot Diag: Dot Diag:

Wants to _________Wants to _________Wants to _________Wants to _________Wants to _________Wants to _________Wants to _________

All ions are ________All ions are ________All ions are ________All ions are ________All ions are ________All ions are ________All ions are ________

Names: Names: Names: Names: Names: Names: Names:

p Block Exceptions:All are positive - need to use Roman numerals!Sn As Se

Pb Sb TeBi Po

Can lose 2 Can lose 3 Can lose 4

Can lose 4 Can lose 5 Can lose 6

7.1 – Ionic Compounds: Ions – d Block

cobalt (II) = Co+2

cobalt (III) = Co+3

copper (I) = Cu+1

copper (II) = Cu+2

chromium (II) = Cr+2

chromium (III) = Cr+3

chromium (VI) = Cr+6

iron (II) = Fe+2

iron (III) = Fe+3

Silver (I) = Ag+1

platinum (II) = Pt+2

platinum (IV) = Pt+4

mercury (II) = Hg+2

Zinc (II) = Zn+2

cadmium (II) = Cd+2

manganese (II) = Mn+2

manganese (IV) = Mn+4

nickel (II) = Ni+2

nickel (III) = Ni+3

gold (III) = Au+3

*Intro Classes can put Roman Numerals on ALL d-block elements*Honors Class must know which elements NEED Roman Numerals

7.1 – Polyatomic IonsThe Tough Stuff!

THE 8 -ATES:• Carbonate CO3

-2

• Nitrate NO3-1

• Sulfate SO4-2

• Chlorate ClO3-1

• Chromate CrO4-2

• Bromate BrO3-1

• Phosphate PO4-3

• Iodate IO3-1

Rules with –ates:1 more oxygen than –ate =

per … ate1 less oxygen than –ate =

…ite2 less oxygens than –ate =

hypo … ite

7.1 – Other Polyatomic Ions

Ammonium NH4+1

Hydronium H3O+1

Peroxide O2-2

Hydroxide OH-1

Cyanide CN-1

7.1 – Ionic Compounds – Names and Formulas

Naming Binary Ionic Compounds:A metal + a nonmetal = IONICName = cation name anion name (w/-ide ending)

-Use Roman Numerals if neededExamples:

7.1 – Ionic Compounds – Names and Formulas

Writing Binary Ionic Formulas:Remember Chapter 6?

New way: Use the swap technique – Number on charge tells you how many of the OTHER element

Examples:

Examples

7.1 – Ionic Compounds – Names and Formulas

Naming Ionic Compounds w/more than 2 elements:

Name = cation name anion name(at least one will be a polyatomic ion)

Examples:

7.1 – Ionic Compounds – Names and Formulas

Writing Ionic Formulas for Ionic Compounds with More Than 2 Elements:

Use the swap techniqueExamples:

7.1 – Molecular Compounds

2 Nonmetals BondedUSE PREFIXES!

Mono=Di=Tri=Tetra=Penta=Hexa=Hepta=Octa=Nona=Deca=

7.1 - Molecular Compounds

Name = prefix first element prefix second element-idePrefix is the quantity of that elementMono is not needed in front of the FIRST element onlyExamples:

7.1 – Acid Naming

• Acids are an specific molecular substance– We will discuss more in Ch. 15

• Two types:– Binary Acids– Oxyacids

7.1 – Acid Naming

• Binary Acids– Consist of ONLY two elements– Usually H + one of Halogens (F, Cl, Br,I)– Hydro…Root of element…ic Acid– Examples:

• HF = • HCl = • HBr = • HI =

7.1 – Acid Naming

• Oxyacids– Acids that contain three elements (H, O, and

usually a third nonmetal element)– Related to the 8-ate polyatomic ions:

If ion ends in…. Acid will end in….

…ate (8-ate you memorized) …ic

…ite (1 less O) …ous

Hypo…ite (2 less O) Hypo…ous

Per…ate (1 more O) Per…ic

7.1 – Acid Naming

• Oxyacids– Examples:

• HClO3

• HClO2

• HClO• HClO4

7.1 – Review• Practice Problems

– Ions– Naming Ionic Compounds– Writing Ionic Compound Formulas– Naming Molecular Compounds– Writing Molecular Compound Formulas– Acid Naming

• Binary• Oxyacids

7.2 – Oxidation Numbers-Show distribution of electrons-Negative means “stronger element / ‘grabbing’ electrons” and positive

means “weaker element / losing electrons”Rules:1. Uncombined element has oxidation number = 02. Monatomic ion has oxidation number = charge3. If in a compound:

A. Start with the element on the right. It has oxidation number = charge if it was a negative ion.B. If more than 2 atoms, go next to the element on the left, it has oxidation number = charge if it was a positive ion.C. Hydrogen can be –1 if it is on the right or +1 if it is the one on the left.

4. Sum of all oxidation numbers in a neutral compound = 05. Sum of all oxidation numbers in a polyatomic ion = charge on ion

7.2 – Oxidation NumbersPractice Problems:

7.3 – Molar Mass

Molar Mass = Sum of Average Atomic Masses for all elements in a compound from periodic table. Unit = g/mol

Examples:

Using Molar Mass

Can be used as a conversion factor

O2 = 32 grams / 1 mole OR 1 mole / 32 grams

Examples:

Percent Composition

Percent by mass of an element in a compound(Mass element / molar mass) x 100 = % composition

Examples:

Empirical Formulas

Empirical Formula = The simplest (most reduced) formulaExample: The empirical formula of glucose (C6H12O6) is….

Steps:1. Find moles of each element (divide given by molar

mass of element)2. Divide all moles by the smallest number of moles3. Write formula with subscripts 4. If .5s multiply all by 2

Empirical Formulas Calculations

Examples:

Molecular Formulas

This is the NON-Reduced formula (ex – glucose = C6H12O6)

Need to have the Empirical Formula and the molecule’s Molar Mass (AKA Molecular Mass)

Step One: Molecular Mass = x Empirical Form MassStep Two: x multiplied by the Empirical Form

Molecular FormulasExamples: