Presentation on theme: "Wednesday, November Compound Naming Problems: Questions?"— Presentation transcript:
1 Wednesday, November 28 16-30 Compound Naming Problems: Questions? 31-40 = Homework TonightMust complete sheet to retake Quiz 1 & 2Thursday= Polyatomic Ions (Quiz #1 Retake)Friday= Acids (Quiz #2 Retake)Take out Ch.7 ½ Packet from yesterday
2 Thursday, November 29 Turn in Compound Naming Race sheet Ch. 7 Test Next Thursday!Thursday, November 29Turn in Compound Naming Race sheetat Front if you intend to retake quizFriday= Acids (Quiz #2 Retake)Take out sheet of paper, title “Polyatomic Ions (Quiz #1 Retake)”YOU WILL NEED CALCULATOR TODAY!
3 Friday, November 30 Take out sheet of paper, title Ch. 7 Test Next Thursday!Friday, November 30Take out sheet of paper, title“Acids (Quiz #2 Retake)” if you are retaking quiz 2You will need Formula Mass notes and calculator today.
4 Nomenclature QUIZ 1 RETAKE Write the compound name:CaBr2Na2CO3Ca(OH)2Write the formula:Magnesium CarbonateCalcium NitriteWrite the ion name or formula that corresponds:NH4 +1SO4 -2SulfiteAsO4 -3PO4 -3Write the ion name or formula that corresponds:ChlorateClO3 -1OH -1CarbonateClO4 -1NO3 -1NO2 -1SulfateCN -1SO3 -2
5 Nomenclature QUIZ 2 RETAKE Write the nomenclature:H2SO4Chloric AcidHydroflouric AcidCH3COOHHClO2Carbonic AcidSulfuric AcidH2SO3Nitric AcidHClH3PO4H2CO3Write the formula name:NaICaONaClCa(OH)2SO3Write the formula:Sodium FluoridePotassium SulfideIron (III) Oxide
6 Chemical Formulas and Compounds Using Chemical Formulas
7 Using Chemical Formulas A chemical formula indicatesthe elements present in a compoundthe relative number of atoms or ions of each element present in a compoundChemical formulas also allow chemists to calculate a number of other characteristic values for a compound:formula massmolar masspercentage composition
8 Using Chemical Formulas Formula MassesThe formula mass of any molecule, formula unit, or ion is the sum of the average atomic masses of all atoms represented in its formulaformula mass of water, H2Oaverage atomic mass of H: 1.01 amuaverage atomic mass of O: amuaverage mass of H2O molecule = amu
9 Using Chemical Formulas Formula MassesThe mass of any unit represented by a chemical formula (H2O, NaCl) can be referred to as the formula mass
10 Using Chemical Formulas Formula MassesSample ProblemFind the formula mass of potassium chlorate, KClO3
11 Using Chemical Formulas Formula MassesSample Problem SolutionThe mass of a formula unit of KClO3 is found by adding the masses of one K atom, one Cl atom, and three O atomsformula mass of KClO3 = amu
12 The MOLE What is a mole? What is a mole of apples? What is a mole of carbon?What is a mole of H2O?
13 Using Chemical Formulas Molar MassesThe molar mass of a substance is equal to the mass in grams of one mole, or approximately × 1023 particles, of the substanceThe 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
14 molar mass of H2O molecule = 18.02 g/mol Molar MassesOne 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 followsA compound’s molar mass is numerically equal to its formula massmolar mass of H2O molecule = g/mol
15 Using Chemical Formulas Formula MassesSample ProblemWhat is the molar mass of barium nitrate, Ba(NO3)2
16 Using Chemical Formulas Formula MassesSample Problem SolutionOne 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 = g/mol
18 Molar Mass Conversions Sample ProblemWhat is the mass in grams of 2.50 mol of oxygen gas (O2)
19 Using Chemical Formulas Molar Mass ConversionsSample Problem SolutionGiven: 2.50 mol O2Unknown: mass of O2 in gramsmoles O2 grams O2amount of O2 (mol) × molar mass of O2 (g/mol) = mass of O2 (g)O2
20 Using Chemical Formulas Molar Mass ConversionsSample ProblemIbuprofen, C13H18O2, is the active ingredient in many nonprescription pain relievers. Its molar mass is g/molIf 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?
21 Molar Mass Conversions Sample Problem SolutionGiven: 33g of C13H18O2, molar mass g/molUnknown: moles C13H18O2molecules C13H18O2total mass of C
22 Molar Mass Conversions Sample Problem Solutiongrams molesmoles moleculesmoles C13H18O moles C grams C
23 Using Chemical Formulas Molar Mass ConversionsSample Problem Solution
24 Percentage Composition It is often useful to know the percentage by mass of a particular element in a chemical compoundTo 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
25 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 compoundThe percentage by mass of each element in a compound is known as the percentage composition of the compound
26 Using Chemical Formulas Molar Mass ConversionsSample ProblemFind the percentage composition of copper(I) sulfide, Cu2S
27 Using Chemical Formulas Molar Mass ConversionsSample Problem SolutionGiven: formula, Cu2SUnknown: percentage composition of Cu2Sformula molar mass mass percentage of each element
28 Molar Mass Conversions copper(I) sulfide, Cu2SSample Problem SolutionMolar mass of Cu2S = g