CONSERVATION OF MASS During a chemical reaction, matter is neither created nor destroyed.  i. e. the number of atoms of each element remains constant


 Gordon McCarthy
 1 years ago
 Views:
Transcription
1 1 CHEMICAL REACTINS Example: Hydrogen + xygen Water H + H Note there is not enough hydrogen to react with oxygen  It is necessary to balance equation. reactants products + H + H (balanced equation) CNSERVATIN F MASS During a chemical reaction, matter is neither created nor destroyed.  i. e. the number of atoms of each element remains constant BALANCING CHEMICAL EQUATINS  ensures # of reactant atoms = # of product atoms CH4 + C + H Cu + S8 CuS Fe3 + C Fe + C Sc3 + H Sc(H)3 CH3NH + C + H + N  Sometimes it is more convenient to balance groups of atoms (polyatomic ions) than individual atoms. AgN3 + CaCl Ca(N3) + AgCl  Balance N3  ions rather than N and atoms. Ba(Cl4) + NaS4 BaS4 + NaCl4  Balance Cl4  and S4  ions.
2 FRMULA AND MLECULAR MASS Formula Mass (Weight) sum of atomic masses in chemical formula Molecular Mass (Weight) same as formula mass for molecular compounds  technically not defined for ionic compounds Clarification of definitions  often the words mass and weight are used interchangeably even though they are technically not the same thing.  often formula mass and molecular mass are used interchangeably even though they are technically not the same things Calculating Formula Mass Example: C3H6 (cyclopropane) 3 (1.011 amu) + 6 ( amu) = amu Example: Ca(H) (calcium hydroxide) amu + ( amu) + ( amu) = amu THE MLE ***A mole is 6.0 x 10 3 items.*** 1 mole = 6.0 x 10 3 items Analogy 1 dozen = 1 items 18 eggs = 1.5 dz.  to convert from eggs from dozen, we need to multiply by conversion factor Example: How many eggs in 3. dozen? Analogy # 1 gross = 144 items Example: How many gross is 68 pencils?
3 3 1 mole = 6.0 x 10 3 items x 10 3 is called Avogadro s number and is abbreviated NA. 6.0 x 10 3 molecules = 1 molemolecule x 10 3 molecules = molemolecule Example: How many moles of atoms is 7.43 x 10 1 atoms? Example: How many moles of ions is.5 x 10 5 ions? Example: How many molecules are in mol of molecules? MLAR MASS Definition of Molar Mass Mass of 1 mole 1 C is g BY DEFINITIN Recall 1 atom of 1 C is amu *This is not a coincidence* Definition of amu and a mole are made to ensure coincidence 1 amu = 1.66 x 107 kg = 1/NA grams 1 molc1 = g molc1 = g gC molC molc g mol C 1 ATMIC MLAR MASS 1 C: 1 atom = 1 amu 1 mol = 1 g M( 1 C) = 1 g/mol 4 Mg: 1 atom = 4 amu 1 mol = 4 g M( 4 Mg) = 4 g/mol 56 Fe: 1 atom = 56 amu 1 mol = 56 g M( 56 Fe) = 56 g/mol C 1
4 AVERAGE ATMIC MLAR MASS  Elements often have two or more naturally occurring isotopes  Average atomic molar mass is the average of all atomic molar masses of the naturally occurring isotopes according to each isotope s relative abundance  Except for units, identical to average atomic mass  Note: mass of isotopes not integers because of nuclear forces Example: Neon nuclide abundance mass(g/mol) 0 Ne 90.48% Ne 0.7% Ne 9.5% M(Ne) = (19.99 g/mol) (0.994 g/mol) (1.991 g/mol) = 0.18 g/mol  Note: example is the same as example for average atomic mass Example: How many moles of atoms are in 96.3 grams of carbon? Example: How much mass does moles of uranium have? FRMULA MLAR MASS  add molar masses for all atoms within a chemical formula Example: ethene, CH4 M(CH4) = x g/mol + 4 x g/mol = g/mol Ethene (ethylene) is used to ripen fresh fruit. It is also used to make polyethylene, which is used to make milk jugs. Example: How many moles are in 538 g of Ba(N3) First calculate formula weight g/mol x g/mol 6 x g/mol g/mol 538g 538g 06. mol g Barium nitrate is used to color fireworks green.
5 5 SCHEME: Converting mass to moles to number Mass (g) M Molar mass Moles (mol) NA Avogadro s number Note: Molar mass and Avogadro s number are conversion factors Number (atoms or molecules) Example: How many atoms are in 0.1 g of He? Example: How many F atoms are in g of CaF? EMPIRICAL FRMULA FRM MASS PERCENT ANALYSIS Given: Percent Mass Composition Find: Empirical Formula Strategy: 1) Assume 100 g of matter. ) Multiply 100 g by mass percent to find amount of each element. 3) Convert mass of each element to moles using molar mass. 4) Find whole number ratios by dividing each number of moles by lowest number of moles.
6 6 Example: Find the empirical formula for a compound with the following mass percentages: % Cl % C.6 % H Cl: g x = g C: g x = g H: g x 0.06 =.6 g 3 H: C: Cl: 4 Empirical Formula is CH3Cl3
7 7 CMBUSTIN ANALYSIS A mass of hydrocarbon is burnt with oxygen to produce C, H and N. From the mass of C, H and N produced and mass of oxygen used, find the empirical formula for the compound. Ultimately, we want to find molar ratios that we ll use to find the empirical formula. 1. Convert mass of C to moles of carbon atoms.  calculation yields moles of carbon in hydrocarbon sample. C (g) + KH (s) KHC3 (s). Convert mass of H to moles of hydrogen atoms.  because there are two moles of hydrogen to one mole of water, multiply result by to yield moles of hydrogen in hydrocarbon sample. H (g) + CaCl (s) CaCl H (s) 3. Convert mass of N to moles of nitrogen atoms.  because there are two moles of nitrogen atoms in one mole of nitrogen molecules, multiply result by to yield moles of nitrogen in hydrocarbon sample. 4. Calculate moles of oxygen in products.  moles of oxygen = moles of C + moles of H 5. Calculate moles of oxygen in hydrocarbon  moles of hydrocarbon oxygen = moles of oxygen atoms in products moles of oxygen atoms used 6. Divide molar amounts by smallest of the values to find molar ratios in terms of whole numbers.
8 Example: Find the empirical formula for a sample of hydrocarbon that produces 7.61 g of C, 4.15 g of H and uses 7.39 g of during combustion. 8 Moles of carbon Moles of hydrogen C C 7.61g 0.173molC 44.0 gc C H mol 18.0 g H 4.15g 0.46 H H H Moles of oxygen in products C mol H mol products 7.61g 4.15g 44.0g 18.0g Moles of oxygen in hydrocarbon C C H H mol mol mol mol hydrocarbon products mol mol 7.39g 3.0g mol 0.46 mol 0.115mol mol Molar ratios 0.173molC 3mol mol mol 0.46H 4 mol mol C H Empirical formula is C3H8
9 THERETICAL STICHIMETRY  coefficients of balanced equations relate moles of reactants to moles of products Example: N (g) + 3 H (g) NH3 (g) mole of N is stoichiometrically equivalent to moles of NH3.  in other words, for every 1 mole of N reacted, moles of NH3 are produced.  N mol NH 3  equivalence is only true for specific chemical reaction  equivalence can be considered a conversion factor N mol NH 3 N mol NH or mol NH N other equivalences are  N 3molH  3mol H mol NH 3 The Haber process is essential in the production of fertilizer, which in turn, is essential for sustenance of Earth s 7,000,000,000 people. Example: a) What are all of the stoichiometric equivalences for the reaction, CH (g) + 5 (g) 4 C (g) + H (g)? molch 5mol C H molc CH H 5mol 4molC 5mol mol H mol C H b) How many moles of carbon dioxide are formed when 5 moles of acetylene (CH) is combusted? c) How many moles of oxygen are needed to fully burn 9.8 moles of acetylene (CH)? Acetylene is a welder s fuel.
10 PRACTICAL STICHIMETRY  can t measure moles directly in the real world.  must measure amount of substance with grams. *** cannot compare substances stoichiometrically by mass, must convert to moles.*** 10 SCHEME: M Molar mass Mass of reactant (g) Mass of product (g) M Molar mass Moles of reactant (mol) Balanced equation Moles of product (mol) Example: For the reaction, NH3 (g) + HCl (g) NH4Cl (s), a) how much NH3 is needed to react with 9.3 g of HCl? 1) First convert grams of reactant to moles of reactant ) Compare moles of one reactant to other reactant. 3) Convert moles of other reactant to grams. The reaction of ammonia with hydrogen chloride gas is used to create a smokescreen. b) How much ammonium chloride is produced when 9.3 g of HCl is fully reacted?  Note with dimensional analysis, we can do problems all on one line.
11 Example: For the reaction 4BaC3 (s) + Y(C3)3 (s) + 6 CuC3 (s) YBaCu37 (s) + 13 C (g) + 3 (g) a) calculate how many grams of CuC3 is needed to fully react with g of BaC3, 11 b) calculate how many grams of YBaCu37 is formed from g of BaC3 fully reacting. Yttrium barium copper oxide (YBC) is a superconducting ceramic. It is superconducting below a temperature of 95 K.
12 1 Example: Epsom salts are used in foot baths to soften skin and relieve itching. Epsom salt is a hydrated crystal of magnesium sulfate. An intense heat source such as a Bunsen burner flame can drive off the water from the crystal leaving the anhydrous salt. Given the data below, write the correct chemical formula for Epsom salt. Mass of beaker Mass of beaker and Epsom salt Mass of beaker and dried salt g g g Find the mass of the Epsom salt g g = g Find the mass of the dried salt g g = 5.48 g Find the mass of water that has left g 5.48 g = g Find the moles of water Find the moles of MgS4 Find the number of water molecules per MgS4 unit The correct chemical formula is MgS4 7 H
13 13 LIMITING REAGENTS  ften starting materials are not available in proper stoichiometric proportions.  Given unbalanced amounts of reactants, we would like to know how much product could be produced. Analogy: Bicycle Factory The equation to make a bicycle is wheels + 1 frame + 1 handlebar 1 bicycle If the parts inventory is as follows: 40 wheels 150 frames 135 handlebars, we ask ourselves  What reactant limits production?  How much product can be produced? Limiting reactant: wheels Production: 10 bicycles ***In limiting reagent problems, we need to compare moles to moles***  need to convert all masses to moles  To find limiting reactant, calculate number of moles of product formed from each number of moles of reactant  Limiting reactant will yield lowest number of moles produced. (The lowest number of moles produced is the actual number of moles of product produced.) Example: For the reaction S (g) + (g) + H (l) HS4 (aq), if 5.6 mol of S, 4.8 mol of and 6.0 mol of H are reacted together, a) how many moles of HS4 are produced? HS4 For the S: 56. mols 56. mol molhs4 For the : 48. mol 96. mol S H S 4 HS4 H S4 For the H: 6.0 molh 6.0 molh S4 H S is limiting reactant and therefore 5.6 moles of HS4 is produced.
14 b) how much is remaining after reaction is complete?  to answer the question, we need to know how much was used.  then remaining is the amount of reacted subtracted from the starting amount of. used: 56. mols 8. mol mol S remaining = starting used = 4.8 mol.8 mol =.0 mol Sulfur dioxide is a pollutant from burning coal that is a contributor to acid rain. Sulfur dioxide is removed from air with calcium oxide.s (g) + Ca (s) CaS 3 (s) 14 Example: For the reaction Zn (s) + CuCl (aq) ZnCl (aq) + Cu (s) a) How much copper metal is produced from the reaction of.00 g of Zn and.00 g of CuCl? Thus CuCl is the limiting reactant and the amount of copper produced is b) How much reactant was left over? Since CuCl is the limiting reactant, all of it was consumed in the reaction. Thus some Zn is left over. Moles of Zn used Zn molcu mol Total original moles moles used = moles left over Cu Zn
15 15 REACTIN YIELDS  an actual chemical process is rarely perfect  actual yield is less than theoretical perfect yield  we have been calculating theoretical yields  we often want to compare actual yield to theoretical yield Example: For the reaction Cr3 (s) + Al (s) Cr (s) + Al3 (s) 18.7 g of Chromium (III) oxide reacts to form 10.8 g of chromium metal. What the percent yield of this process? % yield Theoretical yield of chromium metal is actual yield 100% theoretical yield Thus the percent yield is
THE MOLE / COUNTING IN CHEMISTRY
1 THE MOLE / COUNTING IN CHEMISTRY ***A mole is 6.0 x 10 items.*** 1 mole = 6.0 x 10 items 1 mole = 60, 00, 000, 000, 000, 000, 000, 000 items Analogy #1 1 dozen = 1 items 18 eggs = 1.5 dz.  to convert
More informationMOLE: Amount of a substance containing 6.02x10 23 particles THE MOLE
THE MLE A sensitive balance can weight to the nearest 0.0001 g, but a typical atom has a mass of only 0.000 000 000 000 000 000 000 01 g Is it possible to keep track of atoms by counting them? Yes, but
More informationChapter 3 Stoichiometry: Calculations with Chemical Formulas and Equations
Chapter 3 Stoichiometry: Calculations with Chemical Formulas and Equations Recommended Text Problems 1, 4, 7, 9, 11, 13, 15, 17, 19, 23cd, 25b, 33, 37, 39, 43, 47, 49c, 51, 57, 61, 63c, 67, 69, 71, 73,
More informationStoichiometry: Calculations with Chemical Formulas and Equations. In this chapter. The Mole. Sponsored by Lavoisier & Avogadro.
Stoichiometry: Calculations with Chemical Formulas and Equations Sponsored by Lavoisier & Avogadro Chapter 3 In this chapter The mole concept. Relationships between chemical formulas, atomic masses and
More informationStoichiometry: Calculations with Chemical Formulas and Equations. In this chapter
Stoichiometry: Calculations with Chemical Formulas and Equations Sponsored by Lavoisier & Avogadro Chapter 3 In this chapter The mole concept. Relationships between chemical formulas, atomic masses and
More informationChapter 3 Stoichiometry: Ratios of Combination
Chapter 3 Stoichiometry: Ratios of Combination 1 3.1 Molecular and Formula Masses 3.2 Percent Composition of Compounds 3.3 Chemical Equations 3.4 The Mole and Molar Mass 3.5 Combustion Analysis 3.6 Calculations
More informationChapter 2 Stoichiometry describes the quantitative relationships among elements
Chapter 2 Stoichiometry describes the quantitative relationships among elements 1. in compounds (composition stoichiometry) 2. in chemical changes (reaction stoichiometry) Dalton s Atomic Theory summarized
More informationChemical Reactions. Chemical Equations. Mole as Conversion Factor: To convert between number of particles and an equivalent number of moles:
Quantities of Reactants and Products CHAPTER 3 Chemical Reactions Stoichiometry Application of The Law of Conservation of Matter Chemical bookkeeping Chemical Equations Chemical equations: Describe proportions
More informationChapter 3: Stoichiometry
Chapter 3: Stoichiometry Key Skills: Balance chemical equations Predict the products of simple combination, decomposition, and combustion reactions. Calculate formula weights Convert grams to moles and
More informationChapter 3 Stoichiometry: Calculations with Chemical Formulas and Equations
Chapter 3 Stoichiometry: Calculations with Chemical Formulas and Equations 3.1 Chemical Equations A chemical equation describes a chemical reaction. Reactants (states) Products (states) A(g) + B(l) C(s)
More informationChapter 3. Stoichiometry: Ratios of Combination. Insert picture from First page of chapter. Copyright McGrawHill 2009 1
Chapter 3 Insert picture from First page of chapter Stoichiometry: Ratios of Combination Copyright McGrawHill 2009 1 3.1 Molecular and Formula Masses Molecular mass  (molecular weight) The mass in amu
More informationFormulas, Equations, and Moles. + "reacts with" "to produce" Equations must be balanced. Equal amounts of each element on each side of the equation.
Chapter 3 Formulas, Equations, and Moles Chemical Equations 2 2 + 2 2 2 reactants products + "reacts with" "to produce" coefficients  indicate amount of substance Equations must be balanced. Equal amounts
More informationPart One: Mass and Moles of Substance. Molecular Mass = sum of the Atomic Masses in a molecule
CHAPTER THREE: CALCULATIONS WITH CHEMICAL FORMULAS AND EQUATIONS Part One: Mass and Moles of Substance A. Molecular Mass and Formula Mass. (Section 3.1) 1. Just as we can talk about mass of one atom of
More informationChapter 3: Mass Relationships in Chemical Reactions
Chapter 3: Mass Relationships in Chemical Reactions This chapter discusses the masses of atoms and molecules and what happens to them in a chemical change. (Law of Conservation of Mass) 3.1 Atomic Mass
More informationStoichiometry Notes. Review of Moles. Determine the molar mass of Ca 3 (PO 4 ) 2. How many moles of H 2 O are in 9.87 grams of H 2 O?
Stoichiometry Notes Review of Moles Determine the molar mass of Ca 3 (PO 4 ) 2 How many moles of H 2 O are in 9.87 grams of H 2 O? How many molecules are in 87.9 grams of nitrogen dioxide? How many oxygen
More informationChapter 3. Chapter The mole conveniently links mass to number of atoms/molecules. Atomic, Molecular and Formula Mass
Chapter 3 The Mole: Relating the Microscopic World of Atoms to Laboratory Measurements 1 3.1 The mole conveniently links mass to number of atoms/molecules Atoms are very small (as we already know) So if
More informationE AMA. Mass = Molar Mass. Stoichiometry.notebook. August 12, How to find moles. Find Grams. A) 0.5 moles of H2O
Stoichiometry.notebook How to find moles moles!!! E AMA Mass = Molar Mass PV = RT MxV= Aug 19 8:54 AM Find Moles (Don't use a calculator, approximate) Aug 19 8:54 AM Find Grams A) 80 grams of NaOH (FW
More informationChemical Calculations: The Mole Concept and Chemical Formulas. AW Atomic weight (mass of the atom of an element) was determined by relative weights.
1 Introduction to Chemistry Atomic Weights (Definitions) Chemical Calculations: The Mole Concept and Chemical Formulas AW Atomic weight (mass of the atom of an element) was determined by relative weights.
More information1. P 2 O 5 2. P 5 O 2 3. P 10 O 4 4. P 4 O 10
Teacher: Mr. gerraputa Print Close Name: 1. A chemical formula is an expression used to represent 1. mixtures, only 3. compounds, only 2. elements, only 4. compounds and elements 2. What is the total number
More informationChapter 3 Chemical Reactions and Reaction Stoichiometry. 許富銀 ( Hsu FuYin)
Chapter 3 Chemical Reactions and Reaction Stoichiometry 許富銀 ( Hsu FuYin) 1 Stoichiometry The study of the numerical relationship between chemical quantities in a chemical reaction is called stoichiometry.
More informationUnit 6 The Mole Concept
Chemistry Form 3 Page 62 Ms. R. Buttigieg Unit 6 The Mole Concept See Chemistry for You Chapter 28 pg. 352363 See GCSE Chemistry Chapter 5 pg. 7079 6.1 Relative atomic mass. The relative atomic mass
More informationChapter 6 Chemical reactions Classification And Mass Relationships. Chapter 6 1
Chapter 6 Chemical reactions Classification And Mass Relationships Chapter 6 1 Chemical reactions and Chemical Equations Balancing Chemical Equations Mole, Avogadro s Number Stoichiometric Problems Percent
More informationMass and Moles of a Substance
Chapter Three Calculations with Chemical Formulas and Equations Mass and Moles of a Substance Chemistry requires a method for determining the numbers of molecules in a given mass of a substance. This allows
More information1. Identify the mass law that the following observation demonstrates. (1 pt)
Quiz 2 Take out 1 sheet of paper and your calculator (remove covers). Please place all books on the floor. You have 10 minutes from START. Show all work to get points. Please stop when asked to stop. 1.
More informationPractice questions for Ch. 3
Name: Class: Date: ID: A Practice questions for Ch. 3 1. A hypothetical element consists of two isotopes of masses 69.95 amu and 71.95 amu with abundances of 25.7% and 74.3%, respectively. What is the
More informationChemistry Chapter 9 Study Guide
Chemistry Chapter 9 Study Guide Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The coefficients in a chemical equation represent the a. masses, in grams,
More informationStoichiometry. Chapter 3. Atomic mass is the mass of an atom in atomic mass units (amu) Macro World grams. Micro World atoms & molecules
1 Stoichiometry Chapter 3 Copyright The McGrawHill Companies, Inc. Permission required for reproduction or display. 2 Micro World atoms & molecules Macro World grams Atomic mass is the mass of an atom
More informationChemical Calculations: Formula Masses, Moles, and Chemical Equations
Chemical Calculations: Formula Masses, Moles, and Chemical Equations Atomic Mass & Formula Mass Recall from Chapter Three that the average mass of an atom of a given element can be found on the periodic
More informationChapter 3! Stoichiometry: Calculations with Chemical Formulas and Equations. Stoichiometry
Chapter 3! : Calculations with Chemical Formulas and Equations Anatomy of a Chemical Equation CH 4 (g) + 2O 2 (g) CO 2 (g) + 2 H 2 O (g) Anatomy of a Chemical Equation CH 4 (g) + 2 O 2 (g) CO 2 (g) + 2
More informationStudy Guide For Chapter 7
Name: Class: Date: ID: A Study Guide For Chapter 7 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The number of atoms in a mole of any pure substance
More informationPacket'5b:'The'Mathematics'of'Formulas'and'Equations! 1!
Packet'5b:'The'Mathematics'of'Formulas'and'Equations 1 Moles THE MOLE: Bridge between the visible and invisible world A represents a quantity: particles Just like a is 12 Just as you can have a dozen eggs
More informationHonors Chemistry: Unit 6 Test Stoichiometry PRACTICE TEST ANSWER KEY Page 1. A chemical equation. (C4.4)
Honors Chemistry: Unit 6 Test Stoichiometry PRACTICE TEST ANSWER KEY Page 1 1. 2. 3. 4. 5. 6. Question What is a symbolic representation of a chemical reaction? What 3 things (values) is a mole of a chemical
More informationUNIT 5: MOLES & STOICHIOMETRY
*STUDENT* UNIT 5: *STUDENT* MOLES & STOICHIOMETRY VOCABULARY: 1. Mole 2. Formula mass (FM) 3. Gram formula mass (GFM) 4. Coefficient 5. Subscript 6. Species 7. Law of conservation of mass 8. Law of conservation
More informationChem 1100 Chapter Three Study Guide Answers Outline I. Molar Mass and Moles A. Calculations of Molar Masses
Chem 1100 Chapter Three Study Guide Answers Outline I. Molar Mass and Moles A. Calculations of Molar Masses B. Calculations of moles C. Calculations of number of atoms from moles/molar masses 1. Avagadro
More informationCHEMISTRY Practice exam #2 answer key September 24, 2010
CHEMISTRY 12307 Practice exam #2 answer key September 24, 2010 PART I: MULTIPLE CHOICE 1. An atom of bromine has a mass about four times greater than that of an atom of neon. How many grams of neon will
More informationMass Relationships in Chemical Reactions
Mass Relationships in Chemical Reactions Chapter 3 Copyright The McGrawHill Companies, Inc. Permission required for reproduction or display. Micro World atoms & molecules Macro World grams Atomic mass
More informationChapter 3 Practice Problems
Chapter 3 Practice Problems What is the molecular mass of C 9 H 8 O 4 (aspirin) MgSO 4. 4H 2 O The Mole: Relating the Microscopic World of Atoms to Laboratory Measurements 1 4 3.1 The mole conveniently
More informationChapter 3 Calculation with Chemical Formulas and Equations
Chapter 3 Calculation with Chemical Formulas and Equations Practical Applications of Chemistry Determining chemical formula of a substance Predicting the amount of substances consumed during a reaction
More informationChapter 3 Stoichiometry: Calculations with Chemical Formulas and Equations
CHE11 Chapter Chapter Stoichiometry: Calculations with Chemical Formulas and Equations 1. When the following equation is balanced, the coefficients are. NH (g) + O (g) NO (g) + H O (g) (a). 1, 1, 1, 1
More informationCHAPTER 3 STOICHIOMETRY OF FORMULAS AND EQUATIONS
CHAPTER 3 STOICHIOMETRY OF FORMULAS AND EQUATIONS FOLLOW UP PROBLEMS 3.1A Plan: The mass of carbon must be changed from mg to g. The molar mass of carbon can then be used to determine the number of moles.
More informationCHM1 Review for Exam 11
Topics 1. Balancing a. Lowest whole number ratios b. Mole ratios 2. Moles/Avagadro s number 3. Stoichiometry Calculations a. MoleMole b. MassMole c. MassMass i. Gram formula mass d. MassVolume e. VolumeVolume
More informationChemistry 1 Review. 1. Round the following to the correct number of significant figures:
Chemistry 1 Review 1. Round the following to the correct number of significant figures: a) 0.00342892 (3 sig. fig.) b) 3423 (2 sig. fig.) c) 144.98 (1 sig. fig.) 2. Make sure the answers to the following
More informationChapter 3 Stoichiometry: Calculations with Chemical Formulas and Equations
Chemistry, The Central Science, 11th edition Theodore L. Brown, H. Eugene LeMay, Jr., and Bruce E. Bursten Chapter 3 : Calculations with Chemical Formulas and Equations John D. Bookstaver St. Charles Community
More informationChemistry I: Using Chemical Formulas. Formula Mass The sum of the average atomic masses of all elements in the compound. Units are amu.
Chemistry I: Using Chemical Formulas Formula Mass The sum of the average atomic masses of all elements in the compound. Units are amu. Molar Mass  The mass in grams of 1 mole of a substance. Substance
More informationSample Problem: Find the percentage composition of MgCO 3.
Chemistry H: Form TR4.5A TEST 4 REVIEW Name Date Period Test Review # 4 Formula Mass. The masses of ionic and covalent compounds are found the same way from the formula. The atomic masses of the elements
More information1. How many hydrogen atoms are in 1.00 g of hydrogen?
MOLES AND CALCULATIONS USING THE MOLE CONCEPT INTRODUCTORY TERMS A. What is an amu? 1.66 x 1024 g B. We need a conversion to the macroscopic world. 1. How many hydrogen atoms are in 1.00 g of hydrogen?
More informationThe Mole Concept. The Mole. Masses of molecules
The Mole Concept Ron Robertson r2 c:\files\courses\111020\2010 final slides for web\mole concept.docx The Mole The mole is a unit of measurement equal to 6.022 x 10 23 things (to 4 sf) just like there
More informationStoichiometry. What is the atomic mass for carbon? For zinc?
Stoichiometry Atomic Mass (atomic weight) Atoms are so small, it is difficult to discuss how much they weigh in grams We use atomic mass units an atomic mass unit (AMU) is one twelfth the mass of the catbon12
More informationChapter 3. Chemical Reactions and Reaction Stoichiometry. Lecture Presentation. James F. Kirby Quinnipiac University Hamden, CT
Lecture Presentation Chapter 3 Chemical Reactions and Reaction James F. Kirby Quinnipiac University Hamden, CT The study of the mass relationships in chemistry Based on the Law of Conservation of Mass
More informationMass Relationships in Chemical Reactions
Mass Relationships in Chemical Reactions Chapter 3 Copyright The McGrawHill Companies, Inc. Permission required for reproduction or display. Micro World atoms & molecules Macro World grams Atomic mass
More informationFormulae, stoichiometry and the mole concept
3 Formulae, stoichiometry and the mole concept Content 3.1 Symbols, Formulae and Chemical equations 3.2 Concept of Relative Mass 3.3 Mole Concept and Stoichiometry Learning Outcomes Candidates should be
More informationThe Mole & Chemical Composition. Chapter 8
The Mole & Chemical Composition Chapter 8 The Mole A mole of anything is 6.02214 x 10 23 of that thing. In Chemistry, we work with very small particles, so we must work with a very large quantity of them.
More informationMOLE. Chapter #3 : Stoichiometry. Mole  Mass Relationships of Elements
Chapter #3 : Stoichiometry MOLE The Mole is based upon the definition: The amount of substance that contains as many elementary parts (atoms, molecules, or other?) as there are atoms in exactly 12 grams
More informationAtomic Mass. They are not whole numbers. Examples. The Mole. The Mole
Atomic Mass Atoms are so small, it is difficult to discuss how much they weigh in grams Use atomic mass units. an atomic mass unit (amu) is one twelfth the mass of a carbon12 atom This gives us a basis
More informationThe mass of the formula unit is called the formula mass Formula masses are calculated the same way as molecular masses
Chapter 4: The Mole Atomic mass provides a means to count atoms by measuring the mass of a sample The periodic table on the inside cover of the text gives atomic masses of the elements The mass of an atom
More informationY (3) XY 2 (2) X 2 Y (4) XY 3
1. Which represents both an empirical and a molecular formula (1) P 2 5 (3) C 3 (2) N 2 4 (4) C 6 H 12 6 2. What is the empirical formula of a compound with the molecular formula C 6 H 12 6 (1) C 4 4 (3)
More informationChapter 3 Mass Relationships in Chemical Reactions
Chapter 3 Mass Relationships in Chemical Reactions Student: 1. An atom of bromine has a mass about four times greater than that of an atom of neon. Which choice makes the correct comparison of the relative
More information7 Quantitative Composition of Compounds. Chapter Outline. The Mole. The Mole. The Mole. The Mole 6/8/2016
7 Quantitative Composition of Compounds Chapter Outline 7.1 The Mole 7.2 7.3 Percent Composition of Compounds 7.4 7.5 Black pearls are composed of calcium carbonate, CaCO 3. The pearls can be measured
More informationChapter 6 Chemical Calculations
Chapter 6 Chemical Calculations 1 Submicroscopic Macroscopic 2 Chapter Outline 1. Formula Masses (Ch 6.1) 2. Percent Composition (supplemental material) 3. The Mole & Avogadro s Number (Ch 6.2) 4. Molar
More informationMASS RELATIONS IN CHEMISTRY; STOICHIOMETRY
MASS RELATIONS IN CHEMISTRY; STOICHIOMETRY [MH5; Ch. 3] Each element has its own unique mass. The mass of each element is found on the Periodic Table under the chemical symbol for the element (it is usually
More informationChapter 4 Chemical Equations & Stoichiometry
Chapter 4 Chemical Equations & Stoichiometry Chemical reactions are best described using equations which tells us what compounds we started with (reactants), what we did to them (reaction conditions) and
More informationIB Chemistry 1 Mole. One atom of C12 has a mass of 12 amu. One mole of C12 has a mass of 12 g. Grams we can use more easily.
The Mole Atomic mass units and atoms are not convenient units to work with. The concept of the mole was invented. This was the number of atoms of carbon12 that were needed to make 12 g of carbon. 1 mole
More informationChapter 7. Bellringer. Table of Contents. Chapter 7. Chapter 7. Objectives. Avogadro s Number and the Mole. Chapter 7. Chapter 7
The Mole and Chemical Table of Contents Chemical Formulas Bellringer List as many common counting units as you can. Determine how many groups of each unit in your list are present in each of the following
More informationCHAPTER 2: ATOMS, MOLECULES AND
CHAPTER 2: ATOMS, MOLECULES AND IONS Atom: Basic unit of matter. Smallest particle of the element which retain the properties of that element. Eg: Oxygen, Hydrogen Molecules: Two or more atoms (same or
More informationStoichiometry: Calculations with Chemical Formulas and Equations
Stoichiometry: Calculations with Chemical Formulas and Equations Law of Conservation of Mass We may lay it down as an incontestable axiom that, in all the operations of art and nature, nothing is created;
More informationCHEM Fall 2004
CHEM 14104 Fall 2004 Exam # 2 Name Date 1. (2 points) How many atoms or molecules is a mole. Avogadro s number of specific kind of atom or molecule. 2. (3 points) Circle all the ion pairs which can form
More informationMOLE CONVERSION PROBLEMS. 2. How many moles are present in 34 grams of Cu(OH) 2? [0.35 moles]
MOLE CONVERSION PROBLEMS 1. What is the molar mass of MgO? [40.31 g/mol] 2. How many moles are present in 34 grams of Cu(OH) 2? [0.35 moles] 3. How many moles are present in 2.5 x 10 23 molecules of CH
More informationTOPIC 9. CHEMICAL CALCULATIONS III  stoichiometry.
TOPIC 9. CHEMICAL CALCULATIONS III  stoichiometry. Stoichiometric calculations. By combining a knowledge of balancing equations with the concept of the mole, it is possible to easily calculate the masses
More informationgas =( ); liquid = ( ); solid = ( ); aqueous = ( )
Chapter 4 Quantities of Reactants and Products 4.1 Chemical Equations (p. 124) A chemical equation is a shorthand description of a chemical reaction using symbols and formulas to represent the elements
More informationDo Now CHEMICAL REACTIONS. Chemical Reaction. chemical reaction. Chemical Equations. Evidence
Do Now CHEMICAL REACTIONS What are some signs that a chemical change may have taken place? Where are the reactants and products in a reaction? What do they represent? Describe the law of conservation of
More informationCHAPTER 3: Stoichiometry I: Equations, the Mole, and Chemical Formulas
CHAPTER 3: Stoichiometry I: Equations, the Mole, and Chemical Formulas 3.1 Chemical Equations C 5 H 1 + O H O + CO reactants products Use subscripts (s), (l), (g), (aq) to indicate physical states Balancing
More informationThe Mole Concept and Atoms
Copyright The McGrawHill Companies, Inc. Permission required for reproduction or display. Chapter 4 24 September 2013 Calculations and the Chemical Equation The Mole Concept and Atoms Atoms are exceedingly
More informationChapter 3: Stoichiometry
Chapter 3: Stoichiometry Goal is to understand and become proficient at working with: 1. Avogadro's Number, molar mass and converting between mass and moles (REVIEW). 2. empirical formulas from analysis.
More information0.786 mol carbon dioxide to grams g lithium carbonate to mol
1 2 Convert: 2.54 x 10 22 atoms of Cr to mol 4.32 mol NaCl to grams 0.786 mol carbon dioxide to grams 2.67 g lithium carbonate to mol 1.000 atom of C 12 to grams 3 Convert: 2.54 x 10 22 atoms of Cr to
More informationCHEMISTRY. (i) It failed to explain how atoms of different elements differ from each other.
CHEMISTRY MOLE CONCEPT DALTON S ATOMIC THEORY By observing the laws of chemical combination, John Dalton proposed an atomic theory of matter. The main points of Dalton s atomic theory are as follows: (i)
More informationCh 3 Stoichiometry. Topics: Atomic Mass, Moles, Molar Mass, % Composition, Empirical and Molecular Formulas, Equations, Stoichiometric Calculations
Ch 3 Stoichiometry Topics: Atomic Mass, Moles, Molar Mass, % Composition, Empirical and Molecular Formulas, Equations, Stoichiometric Calculations Jul 26 11:46 AM 1 Ch 3 Stoichiometry I CAN: Connect the
More informationSubscripts and Coefficients Give Different Information
Chapter 3: Stoichiometry Goal is to understand and become proficient at working with: 1. Chemical equations (Balancing REVIEW) 2. Some simple patterns of reactivity 3. Formula weights (REVIEW) 4. Avogadro's
More information6 The mole. 6.1 Moles and masses. The big picture. The mole concept The mass of an atom of carbon12 is taken as 12. So the A r. Sample calculations
6 The mole The big picture The M r of hydrogen, H 2, is 2. The M r of oxygen, 2, is 32. The mole concept tells us that if we could weigh out exactly 2 g of oxygen and 32 g of hydrogen, they would both
More informationChapter 3 Mass Percent and Empirical Formula. Dr. Sapna Gupta
Chapter 3 Mass Percent and Empirical Formula Dr. Sapna Gupta Molecular and Formula Mass Molecular mass is for molecules (covalent compounds) Formula mass is for ionic compounds. Masses are calculated by
More information1) Convert the following
1) Convert the following 1) 125 g to Kg 6) 26.9 dm 3 to cm 3 11) 1.8µL to cm 3 16) 4.8 lb to Kg 21) 23C to K 1.25 x 101 Kg 2) 21.3 Km to cm 2.13 x 10 6 cm 2.69 x 10 3 cm 3 7) 18.2 ml to cm 3 1.82 x 10
More informationLecture 5, The Mole. What is a mole?
Lecture 5, The Mole What is a mole? Moles Atomic mass unit and the mole amu definition: 12 C = 12 amu. The atomic mass unit is defined this way. 1 amu = 1.6605 x 1024 g How many 12 C atoms weigh 12 g?
More informationBALANCING CHEMICAL EQUATIONS
BALANCING CHEMICAL EQUATIONS The Conservation of Matter states that matter can neither be created nor destroyed, it just changes form. If this is the case then we must account for all of the atoms in a
More informationChapter 10 Chemical Quantities
Chapter 10 Chemical Quantities 101 The Mole: A Measurement 102 MoleMass and MoleVolume Relationships 103 Percent Composition and Chemical Formulas 1 Copyright Pearson Education, Inc, or its affiliates
More informationCHEM J2 June /01(a) What is the molarity of the solution formed when 0.50 g of aluminium fluoride is dissolved in ml of water?
CHEM1001 2014J2 June 2014 22/01(a) What is the molarity of the solution formed when 0.50 g of aluminium fluoride is dissolved in 800.0 ml of water? 2 The molar mass of AlF 3 is: molar mass = (26.98 (Al)
More informationThe Mole. Goal is to understand and become proficient at working with: You should also understand molecular, empirical and structural formulas.
Chapter 3: Stoichiometry Goal is to understand and become proficient at working with: 1. Avogadro's Number, molar mass and converting between mass and moles (REVIEW). 2. empirical formulas from analysis.
More informationThe Mole & Stoichiometry
The Mole & CHAPTER 4 Chemistry: The Molecular Nature of Matter, 6 th edition By Jesperson, Brady, & Hyslop CHAPTER 4: The Mole & Learning Objectives! Conversions using moles and Avogadro's number! MoletoMole
More informationChapter 6. Chemical Calculations: Formula Masses, Moles, and Chemical Equations
Chapter 6 Chemical Calculations: Formula Masses, Moles, and Chemical Equations Chapter 6 Chapter Outline 6.1 Formula masses 6.2 The mole: A counting unit for chemists 6.3 The mass of a mole 6.4 Chemical
More informationSCH 4C1 Unit 2 Problem Set Questions taken from Frank Mustoe et all, "Chemistry 11", McGrawHill Ryerson, 2001
SCH 4C1 Unit 2 Problem Set Questions taken from Frank Mustoe et all, "Chemistry 11", McGrawHill Ryerson, 2001 1. A small pin contains 0.0178 mol of iron. How many atoms of iron are in the pin? 2. A sample
More informationW1 WORKSHOP ON STOICHIOMETRY
INTRODUCTION W1 WORKSHOP ON STOICHIOMETRY These notes and exercises are designed to introduce you to the basic concepts required to understand a chemical formula or equation. Relative atomic masses of
More informationStoichiometry. Chapter 3
Stoichiometry Chapter 3 Chemical reactions 1 cup sugar 1 cup butter 2 cups flour 1 ½ cups oats 2K(s) + 2H 2 O(l) H 2 (g) + 2KOH(aq) Chemical Equations C + H 2 O CO + H 2 Represent chemical reactions. +
More informationChapter 11: The Mole 1
Chapter 11: The Mole 1 In what quantity do you purchase the following? Eggs? Shoes? Paper? Roses? Chemists have created their own counting unit to measure atoms, molecules, or formula units in a sample.
More informationCHEMISTRY CP Name: KEY Period: UNIT 5: TEST REVIEW SHEET MOLE CONVERSIONS, EMPIRICAL/MOLECULAR FORMULA, STOICHIOMETRY
CHEMISTRY CP Name: KEY Period: UNIT 5: TEST REVIEW SHEET MOLE CONVERSIONS, EMPIRICAL/MOLECULAR FORMULA, STOICHIOMETRY MOLES AND MOLE CONVERSIONS 1. Things to Know: a. What is a mole? Avogadro s number
More informationStoichiometry Chapter 12. Flowchart. Moles. Practice. Molar Mass of Compounds. Calculations. Stoich.notebook. February 25, 2015
Write the balanced chemical equation: Silver nitrate reacts with barium chloride to form silver chloride and barium nitrate. Stoichiometry Chapter 12 Nov 26 10:49 AM Molar Mass of Compounds Atoms or Molecules
More informationMoles. Balanced chemical equations Molar ratios Mass Composition Empirical and Molecular Mass Predicting Quantities Equations
Moles Balanced chemical equations Molar ratios Mass Composition Empirical and Molecular Mass Predicting Quantities Equations Micro World atoms & molecules Macro World grams Atomic mass is the mass of an
More informationCalculate the molar mass of the following Magnesium nitrate
1.1 Molar Mass 1.2 Molar Mass Molar mass = Molar mass of molecules can be determined from the chemical formula and molar masses of elements Each H 2 O molecule Each mole of H 2 O molecules contains Calculate
More informationWarm Up. What is a mole? What is molar mass? What is Avogadro s number?
Warm Up What is a mole? What is molar mass? What is Avogadro s number? Chapter 7 The Mole and Chemical Compostion Unit Essential Question: HOW CAN CHEMICAL COMPOSITION BE DETERMINED? Lesson Essential Question:
More informationChapter 1: Moles and equations. Learning outcomes. you should be able to:
Chapter 1: Moles and equations 1 Learning outcomes you should be able to: define and use the terms: relative atomic mass, isotopic mass and formula mass based on the 12 C scale perform calculations, including
More informationChapter 3: Formulae, Equations and Moles (Ch3 Chang, Ch3 Jespersen)
Chapter 3: Formulae, Equations and Moles (Ch3 Chang, Ch3 Jespersen) Mass Relationships in Chemical Reactions Atomic mass (or weight) is the mass of an atom in atomic mass units. Molecular weight is the
More informationCalculations and Chemical Equations. Example: Hydrogen atomic weight = 1.008 amu Carbon atomic weight = 12.001 amu
Calculations and Chemical Equations Atomic mass: Mass of an atom of an element, expressed in atomic mass units Atomic mass unit (amu): 1.661 x 1024 g Atomic weight: Average mass of all isotopes of a given
More informationChapter #3 : Stoichiometry  Mole  Mass Relationships in Chemical Systems
Chapter #3 : Stoichiometry  Mole  Mass Relationships in Chemical Systems 1. Atomic Masses 2. The Mole 3. Determining the Formula of an Unknown Compound 4. Writing and Balancing Chemical Equations 5.
More information