Chapter 7 REALLY Important!!!

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

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 (I) = *Hg 2 +2 (Academic: Hg +1 ) 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 Ions The Tough Stuff! THE 8 -ATES: CarbonateCO 3 -2 NitrateNO 3 -1 SulfateSO 4 -2 ChlorateClO 3 -1 ChromateCrO 4 -2 BromateBrO 3 -1 PhosphatePO 4 -3 IodateIO 3 -1 Rules with –ates: 1 more oxygen than –ate = per … ate 1 less oxygen than –ate = …ite 2 less oxygens than –ate = hypo … ite

7.1 – Other Polyatomic Ions AmmoniumNH 4 +1 HydroniumH 3 O +1 PeroxideO 2 -2 HydroxideOH -1 CyanideCN -1 Ions Test Ends Here………

7.1 – Ionic Compounds – Names and Formulas Naming Binary Ionic Compounds: A metal + a nonmetal = IONIC Name = cation name anion name (w/-ide ending) -Use Roman Numerals if needed Examples:

7.1 – Ionic Compounds – Names and Formulas Writing Binary Ionic Formulas: Remember Chapter 6? Use the swap technique – Number on charge tells you how many of the OTHER element New way: Use the swap technique – Number on charge tells you how many of the OTHER element Examples:

More 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 technique Examples:

Ionic Compound Review Formula of: Calcium bromide Copper (II) sulfide Nickel (II) phosphate Strontium hydroxide Barium nitrite Name of: CaO MgCl 2 CrO 3 Fe 3 (PO 4 ) 2 Al 2 (CO 2 ) 3

7.1 – Molecular Compounds 2 Nonmetals Bonded USE PREFIXES! Mono= Di= Tri= Tetra= Penta= Hexa= Hepta= Octa= Nona= Deca=

7.1 - Molecular Compounds Name = prefix first element prefix second element-ide Prefix is the quantity of that element Mono is not needed in front of the FIRST element only Examples:

7.1 – Review Practice Problems -Ions -Naming Ionic Compounds -Writing Ionic Compound Formulas -Naming Molecular Compounds -Writing Molecular Compound Formulas

7.2 – Oxidation Numbers -Show distribution of electrons -Negative means “stronger element / taking electrons” and positive means “weaker element / losing electrons” Rules: 1. Uncombined element has oxidation number = 0 2. Monatomic ion has oxidation number = charge 3. 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. Calculate the remaining element (It may not match what you memorized as the ion charge) 4. Sum of all oxidation numbers in a neutral compound = 0 5. Sum of all oxidation numbers in a polyatomic ion = charge on ion

7.2 – Oxidation Numbers Practice Problems:

7.3 – Molar Mass Molar Mass = Sum of Average Atomic Masses for all elements in a compound. Unit = g/mol Examples: End after first example

Using Molar Mass Can be used as a conversion factor O 2 = 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:

EXPERIMENTALLY Determining Formulas Empirical Formula = The simplest (most reduced) formula Example: The empirical formula of glucose (C 6 H 12 O 6 ) is…. Steps: 1. Find moles of each element 2. Write formula with subscripts 3. Divide all moles by the smallest number of moles 4. If.5s multiply all by 2

Empirical Calculations Examples:

EXPERIMENTALLY Calculating Molecular Formulas This is the NON-Reduced formula (ex – glucose = C 6 H 12 O 6 ) Need to have the Empirical Formula and the molecule’s Molar Mass Examples: -If the empirical formula is BH 3, and the molar mass of the compound is 27.7 g/mol, what is the Molecular Formula?