Wednesday, November 28 16-30 Compound Naming Problems: Questions? 31-40 = Homework Tonight Must complete sheet to retake Quiz 1 & 2 Thursday= Polyatomic Ions (Quiz #1 Retake) Friday= Acids (Quiz #2 Retake) Take out Ch.7 ½ Packet from yesterday

Thursday, November 29 Turn in Compound Naming Race sheet Ch. 7 Test Next Thursday! Thursday, November 29 Turn in Compound Naming Race sheet at Front if you intend to retake quiz Friday= Acids (Quiz #2 Retake) Take out sheet of paper, title “Polyatomic Ions (Quiz #1 Retake)” YOU WILL NEED CALCULATOR TODAY!

Friday, November 30 Take out sheet of paper, title Ch. 7 Test Next Thursday! Friday, November 30 Take out sheet of paper, title “Acids (Quiz #2 Retake)” if you are retaking quiz 2 You will need Formula Mass notes and calculator today.

Nomenclature QUIZ 1 RETAKE Write the compound name: CaBr2 Na2CO3 Ca(OH)2 Write the formula: Magnesium Carbonate Calcium Nitrite Write the ion name or formula that corresponds: NH4 +1 SO4 -2 Sulfite AsO4 -3 PO4 -3 Write the ion name or formula that corresponds: Chlorate ClO3 -1 OH -1 Carbonate ClO4 -1 NO3 -1 NO2 -1 Sulfate CN -1 SO3 -2

Nomenclature QUIZ 2 RETAKE Write the nomenclature: H2SO4 Chloric Acid Hydroflouric Acid CH3COOH HClO2 Carbonic Acid Sulfuric Acid H2SO3 Nitric Acid HCl H3PO4 H2CO3 Write the formula name: NaI CaO NaCl Ca(OH)2 SO3 Write the formula: Sodium Fluoride Potassium Sulfide Iron (III) Oxide

Chemical Formulas and Compounds Using Chemical Formulas

Using Chemical Formulas A chemical formula indicates the elements present in a compound the relative number of atoms or ions of each element present in a compound Chemical formulas also allow chemists to calculate a number of other characteristic values for a compound: formula mass molar mass percentage composition

Using Chemical Formulas Formula Masses The formula mass of any molecule, formula unit, or ion is the sum of the average atomic masses of all atoms represented in its formula formula mass of water, H2O average atomic mass of H: 1.01 amu average atomic mass of O: 16.00 amu average mass of H2O molecule = 18.02 amu

Using Chemical Formulas Formula Masses The mass of any unit represented by a chemical formula (H2O, NaCl) can be referred to as the formula mass

Using Chemical Formulas Formula Masses Sample Problem Find the formula mass of potassium chlorate, KClO3

Using Chemical Formulas Formula Masses Sample Problem Solution The mass of a formula unit of KClO3 is found by adding the masses of one K atom, one Cl atom, and three O atoms formula mass of KClO3 = 122.55 amu

The MOLE What is a mole? What is a mole of apples? What is a mole of carbon? What is a mole of H2O?

Using Chemical Formulas Molar Masses The molar mass of a substance is equal to the mass in grams of one mole, or approximately 6.022 × 1023 particles, of the substance The molar mass of a compound is calculated by adding the masses of the elements present in a mole of the molecules or formula units that make up the compound

molar mass of H2O molecule = 18.02 g/mol Molar Masses One mole of water molecules contains exactly two moles of H atoms and one mole of O atoms. The molar mass of water is calculated as follows A compound’s molar mass is numerically equal to its formula mass molar mass of H2O molecule = 18.02 g/mol

Using Chemical Formulas Formula Masses Sample Problem What is the molar mass of barium nitrate, Ba(NO3)2

Using Chemical Formulas Formula Masses Sample Problem Solution One mole of barium nitrate, contains one mole of Ba, two moles of N (1 × 2), and six moles of O (3 × 2) molar mass of Ba(NO3)2 = 261.35 g/mol

Using Chemical Formulas Molar Mass Conversions

Molar Mass Conversions Sample Problem What is the mass in grams of 2.50 mol of oxygen gas (O2)

Using Chemical Formulas Molar Mass Conversions Sample Problem Solution Given: 2.50 mol O2 Unknown: mass of O2 in grams moles O2 grams O2 amount of O2 (mol) × molar mass of O2 (g/mol) = mass of O2 (g) O2

Using Chemical Formulas Molar Mass Conversions Sample Problem Ibuprofen, C13H18O2, is the active ingredient in many nonprescription pain relievers. Its molar mass is 206.31 g/mol If the tablets in a bottle contain a total of 33g of ibuprofen, how many moles of ibuprofen are in the bottle? How many molecules of ibuprofen are in the bottle? What is the total mass in grams of carbon in 33g of ibuprofen?

Molar Mass Conversions Sample Problem Solution Given: 33g of C13H18O2, molar mass 206.31 g/mol Unknown: moles C13H18O2 molecules C13H18O2 total mass of C

Molar Mass Conversions Sample Problem Solution grams moles moles molecules moles C13H18O2 moles C grams C

Using Chemical Formulas Molar Mass Conversions Sample Problem Solution

Percentage Composition It is often useful to know the percentage by mass of a particular element in a chemical compound To find the mass percentage of an element in a compound, the following equation can be used: The mass percentage of an element in a compound is the same regardless of the sample’s size

Percentage Composition The percentage of an element in a compound can be calculated by determining how many grams of the element are present in one mole of the compound The percentage by mass of each element in a compound is known as the percentage composition of the compound

Using Chemical Formulas Molar Mass Conversions Sample Problem Find the percentage composition of copper(I) sulfide, Cu2S

Using Chemical Formulas Molar Mass Conversions Sample Problem Solution Given: formula, Cu2S Unknown: percentage composition of Cu2S formula molar mass mass percentage of each element

Molar Mass Conversions copper(I) sulfide, Cu2S Sample Problem Solution Molar mass of Cu2S = 159.2 g