Example Problems. PV nt =R so P i. V i n i T i. = P f V f n f T f. (since V and n are constant) = P f T f. T i


 Laurel Douglas
 2 years ago
 Views:
Transcription
1 The temperature of 2.5 L of a gas initially at STP is raised to 250 o C at constant volume. Calculate the final pressure of the gas in atm. PV nt =R so P i V i n i T i = P f V f n f T f or P i T i = P f T f (since V and n are constant)
2 The temperature of 2.5 L of a gas initially at STP is raised to 250 o C at constant volume. Calculate the final pressure of the gas in atm. P f = P i T f T i = 1atm 523 K 298 K = 1.75atm
3 At STP, L of a gas weighs 0.400g. Calculate the molar mass of the gas. M= mrt PV = 0.400g Latm/molK 298 K 1 atm 0.280l =35.0 g/mol
4 A compound has the empirical formula SF 4. At 20 o C, 0.100g of the gaseous compound occupies a volume of 22.1 ml and exerts a pressure of 1.02 atm. What is the molecular formula of the compound? Empirical formula mass = g/mol M = mrt/pv = x x 293/ 1.02 x = 107 g/mol ratio molar mass to empirical formula mass: 107 : 108 1:1 molecular formula: SF 4
5 Methane, the principal component of natural gas, is used for heating and cooking. The combustion process is: CH 4 + 2O 2 CO 2 + 2H 2 O If 15.0 moles of CH 4 are reacted what is the volume of CO 2 in liters produced at 23.0 o C and atm? Mols CO 2 produced = 15.0 mol CH 4 x 1 mol CO 2 /1 mol CH 4 = 15.0 mols V = nrt/p = 15.0 mol x latm/molk x 296 K/ atm = 370 L
6 A piece of sodium metal reacts completely with water as follows: 2Na + 2H 2 O 2NaOH + H 2 The H 2 gas is collected over water at 25.0 o C. The volume of the gas is 246 ml measured at 1.00 atm. Calculate the number of grams of Na used in the reaction (Vapor pressure of water at 25 o C = atm). P T = P H2 + P H2O P H2 = P T  P H2O = = 0.97 atm
7 A piece of sodium metal reacts completely with water as follows: 2Na + 2H 2 O 2NaOH + H 2 The H 2 gas is collected over water at 25.0 o C. The volume of the gas is 246 ml measured at 1.00 atm. Calculate the number of grams of Na used in the reaction (Vapor pressure of water at 25 o C = atm). n H2 = PV/RT = 0.97 atm x L / Latm/molK x 298 K = mol mols Na = mol H 2 x 2 mol Na/ 1 mol H 2 = mol mass Na = mol x g/mol = 0.45g
8 A mixture of Ar and N 2 gases has a density of g/l at STP. What is the mole fraction of the gas? Recalling the equation M = drt/p that can be used to calculate a molar mass from a density: M = g/l x Latm/molK x 298 K / 1 atm = 34.6 g/mol This is intermediate between the molar masses of N 2, g/mol, and Ar, g/mol and is the weighted average of the two... in exactly the same way that the average atomic mass is the weighted average of isotopes.
9 A mixture of Ar and N 2 gases has a density of g/l at STP. What is the mole fraction of the gas? 34.6 = X N2 x (1X N2 ) x X N2 = ( )/( ) = therefore, X Ar = = 0.55
10 A 36.4 L volume of methane gas is heated from 25 o C to 88 o C at constant pressure. What is the final volume of the gas? P f = P i T f T i = 1atm 523 K 298 K =1.75atm
11 Iodine, I 2, reacts with aqueous thiosulfate ion in neutral solution according to the equation: I 2 + S 2 O 3 2 S 4 O I  How many grams of I 2 are present in a solution if ml of M Na 2 S 2 O 3 solution is needed to titrate the I 2 solution? Balance the equation: 1. I 2 + 2e  2I  2S 2 O 3 2 S 4 O e  2. I 2 + 2S 2 O 3 2 S 4 O I 
12 Iodine, I 2, reacts with aqueous thiosulfate ion in neutral solution according to the equation: I 2 + 2S 2 O 3 2 S 4 O I  How many grams of I 2 are present in a solution if ml of M Na 2 S 2 O 3 solution is needed to titrate the I 2 solution? Mols Na 2 S 2 O 3 = L x mol/l = mol mols I 2 = mols Na 2 S 2 O 3 x 1 mol I 2 / 2 mols Na 2 S 2 O 3 = mol mass I 2 = mol x g/mol = g
13 Iron in a sample can be determined by titrating with cerium ion: Fe 2+ + Ce 4+ Fe 3+ + Ce 3+ What is the mass percentage of iron in a sample if titration of g of the sample requires ml of M Ce 4+? Mols Ce 4+ = L x mol/l = mol mols Fe 2+ = mol Ce 4+ x 1 mol Fe 2+ /1 mol Ce 4+ = mol mass Fe = mol x g/mol = g mass %Fe = (0.3292g/1.2284g) x 100 = 26.80%
14 If 1.87 g of acetic acid, C 2 H 4 O 2, reacts with 2.31 g of isopentyl alcohol, C 5 H 12 O to give 2.96 g of isopentyl acetate, C 7 H 14 O 2, what is the percent yield? Balanced equation: C 2 H 4 O 2 + C 5 H 12 O C 7 H 14 O 2 + H 2 O limiting reagent approach 1. mols acetic acid = 1.87 g / g/mol = mol mols C 7 H 14 O 2 = mol 2. mols C 5 H 12 O = 2.31 g / g/mol = mol mols C 7 H 14 O 2 = mol So, C 5 H 12 O is the limiting reagent.
15 If 1.87 g of acetic acid, C 2 H 4 O 2, reacts with 2.31 g of isopentyl alcohol, C 5 H 12 O to give 2.96 g of isopentyl acetate, C 7 H 14 O 2, what is the percent yield? Mass C 7 H 14 O 2 = mol x g/mol = 3.41 g (theoretical yield) Percent yield = (actual yield/theoretical yield) x 100 = (2.96/3.41) x 100 = 78.9%
16 An average cup of coffee contains about 125 mg of caffeine, C 8 H 10 N 4 O 2. How many moles of caffeine are in a cup? How many molecules of caffeine? Mols caffeine = 125 mg x (1 g/1000 mg) / g/mol = 6.44 x 104 mol Molecules caffeine = 6.44 x 104 mol x x molecule/mol = 3.88 x molecules
17 A g sample of a metal carbonate MCO 3 was reacted with ml of M H 2 SO 4 yielding CO 2 gas and an aqueous solution of the metal sulfate. The CO 2 was removed by boiling and the remaining H 2 SO 4 was titrated with M NaOH, requiring ml to reach the endpoint. What is the metal? 2NaOH + H 2 SO 4 Na 2 SO 4 + 2H 2 O starting mols H 2 SO 4 = L x mol/l = mol mols H 2 SO 4 left = mols NaOH x 1 mol H 2 SO 4 / 2 mol NaOH = L x mol/l x ½ = mol mols H 2 SO 4 used = = mol
18 A g sample of a metal carbonate MCO 3 was reacted with ml of M H 2 SO 4 yielding CO 2 gas and an aqueous solution of the metal sulfate. The CO 2 was removed by boiling and the remaining H 2 SO 4 was titrated with M NaOH, requiring ml to reach the endpoint. What is the metal? MCO 3 + H 2 SO 4 MSO 4 + H 2 O mols H 2 SO 4 used = mols MCO 3 = mol molar mass MCO 3 = g/ mol = g/mol mass M in 1 mol = mass MCO 3 mass CO 3 = = g/mol Barium
19 The fictional isotope Xium60 has an atomic mass of units while Xium 70 has an atomic mass of units. The average mass of Xium is units. What is the fractional abundance of Xium 70? Average atomic mass = fraction A x atomic mass A + fraction B x atomic mass B amu = fraction 60 x amu + fraction 70 x = (1  fraction 70) x fraction 70 x fraction 70 =
20 Calculate the number of neutrons in an atom of 239 Pu. Atomic number of plutonium = 94 mass number = 239 = number of neutrons + number of protons number of neutrons = mass number number of protons = = 145
21 Permanganate, MnO 4 , reacts with nitrite, NO 2 , to produce manganese (IV) oxide and nitrate. Balance the equation. 1. half reactions: MnO e  MnO 2 NO 2  NO e  2. balance oxygens: MnO e  MnO 2 + 2H 2 O NO H 2 O NO e  3. balance hydrogens: MnO H + + 3e  MnO 2 + 2H 2 O NO H 2 O NO H + + 2e 
22 Permanganate, MnO 4 , reacts with nitrite, NO 2 , to produce manganese (IV) oxide and nitrate. Balance the equation. 4. add half reactions: 2MnO H + + 6e  2MnO 2 + 4H 2 O 3NO H 2 O 3NO H + + 6e  2MnO H + + 3NO 22MnO 2 + 3NO H 2 O 5. adjust for basic solution if necessary: 2MnO H + + 2OH  + 3NO 22MnO 2 + 3NO H 2 O + 2OH  2MnO H 2 O + 3NO 22MnO 2 + 3NO OH 
23 Acetylsalicylic acid (C 9 H 8 O 4 ) commonly known as "aspirin" is an acid that can ionize to produce one H + ion. A typical aspirin tablet, however, contains only a small amount of the acid. In an experiment to determine its composition, an aspirin tablet was crushed and dissolved in water. It took ml of M NaOH to neutralize the solution. Calculate the number of grams of aspirin in the tablet. HA + NaOH NaA + H 2 O mols NaOH = L x mol/l = mol mols HA = mols NaOH x 1 mol HA / 1 mol NaOH = mol mass HA = mol x g/mol = g
24 Titration with solutions of potassium bromate, KBrO 3, can be used to determine the concentration of As(III). What is the molar concentration of As(III) in a solution if ml of M KBrO3 is needed to titrate ml of the As(III) solution? The (unbalanced) equation is: H 3 AsO 3 + BrO 3  Br  + H 3 AsO 4 1. half reactions: H 3 AsO 3 H 3 AsO 4 + 2e  BrO e  Br  2. balance oxygens: H 3 AsO 3 + H 2 O H 3 AsO 4 + 2e  BrO e  Br  + 3H 2 O
25 Titration with solutions of potassium bromate, KBrO 3, can be used to determine the concentration of As(III). What is the molar concentration of As(III) in a solution if ml of M KBrO3 is needed to titrate ml of the As(III) solution? The (unbalanced) equation is: H 3 AsO 3 + BrO 3  Br  + H 3 AsO 4 3. balance hydrogens: H 3 AsO 3 + H 2 O H 3 AsO 4 + 2H + + 2e  BrO H + + 6e  Br  + 3H 2 O 4. add half reactions: 3H 3 AsO 3 + 3H 2 O 3H 3 AsO 4 + 6H + + 6e  BrO H + + 6e  Br  + 3H 2 O 3H 3 AsO 3 + BrO 33H 3 AsO 4 + Br 
26 Titration with solutions of potassium bromate, KBrO 3, can be used to determine the concentration of As(III). What is the molar concentration of As(III) in a solution if ml of M KBrO3 is needed to titrate ml of the As(III) solution? The (unbalanced) equation is: H 3 AsO 3 + BrO 3  Br  + H 3 AsO 4 Mols BrO 3  = L x mol/l = mol mols H 3 AsO 3 = mols BrO 3  x 3 mol H 3 AsO 3 / 1 mol BrO 3  = mol [H 3 AsO 3 ] = mol / L = mol/l
F321 MOLES. Example If 1 atom has a mass of 1.241 x 1023 g 1 mole of atoms will have a mass of 1.241 x 1023 g x 6.02 x 10 23 = 7.
Moles 1 MOLES The mole the standard unit of amount of a substance (mol) the number of particles in a mole is known as Avogadro s constant (N A ) Avogadro s constant has a value of 6.02 x 10 23 mol 1.
More informationUnit 2: Quantities in Chemistry
Mass, Moles, & Molar Mass Relative quantities of isotopes in a natural occurring element (%) E.g. Carbon has 2 isotopes C12 and C13. Of Carbon s two isotopes, there is 98.9% C12 and 11.1% C13. Find
More informationChemical calculations
Chemical calculations Stoichiometry refers to the quantities of material which react according to a balanced chemical equation. Compounds are formed when atoms combine in fixed proportions. E.g. 2Mg +
More informationneutrons are present?
AP Chem Summer Assignment Worksheet #1 Atomic Structure 1. a) For the ion 39 K +, state how many electrons, how many protons, and how many 19 neutrons are present? b) Which of these particles has the smallest
More informationAS1 MOLES. oxygen molecules have the formula O 2 the relative mass will be 2 x 16 = 32 so the molar mass will be 32g mol 1
Moles 1 MOLES The mole the standard unit of amount of a substance the number of particles in a mole is known as Avogadro s constant (L) Avogadro s constant has a value of 6.023 x 10 23 mol 1. Example
More information2 Stoichiometry: Chemical Arithmetic Formula Conventions (1 of 24) 2 Stoichiometry: Chemical Arithmetic Stoichiometry Terms (2 of 24)
Formula Conventions (1 of 24) Superscripts used to show the charges on ions Mg 2+ the 2 means a 2+ charge (lost 2 electrons) Subscripts used to show numbers of atoms in a formula unit H 2 SO 4 two H s,
More informationMolecular Formula: Example
Molecular Formula: Example A compound is found to contain 85.63% C and 14.37% H by mass. In another experiment its molar mass is found to be 56.1 g/mol. What is its molecular formula? 1 CHAPTER 3 Chemical
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 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 informationUnit 3 Notepack Chapter 7 Chemical Quantities Qualifier for Test
Unit 3 Notepack Chapter 7 Chemical Quantities Qualifier for Test NAME Section 7.1 The Mole: A Measurement of Matter A. What is a mole? 1. Chemistry is a quantitative science. What does this term mean?
More informationCalculation of Molar Masses. Molar Mass. Solutions. Solutions
Molar Mass Molar mass = Mass in grams of one mole of any element, numerically equal to its atomic weight Molar mass of molecules can be determined from the chemical formula and molar masses of elements
More informationUseful only for measuring the mass of very small objects atoms and molecules!
Chapter 9 Chemical Composition (Moles) Which weighs more, 1 atom of He or 1 atom of O? Units of mass: Pound Kilogram Atomic mass unit (AMU) There are others! 1 amu = 1.66 x 1024 grams = mass of a proton
More informationThe Mole. Chapter 10. Dimensional Analysis. The Mole. How much mass is in one atom of carbon12? Molar Mass of Atoms 3/1/2015
The Mole Chapter 10 1 Objectives Use the mole and molar mass to make conversions among moles, mass, and number of particles Determine the percent composition of the components of a compound Calculate empirical
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 informationIB Chemistry. DP Chemistry Review
DP Chemistry Review Topic 1: Quantitative chemistry 1.1 The mole concept and Avogadro s constant Assessment statement Apply the mole concept to substances. Determine the number of particles and the amount
More informationMole Notes.notebook. October 29, 2014
1 2 How do chemists count atoms/formula units/molecules? How do we go from the atomic scale to the scale of everyday measurements (macroscopic scale)? The gateway is the mole! But before we get to the
More informationSolution. Practice Exercise. Concept Exercise
Example Exercise 9.1 Atomic Mass and Avogadro s Number Refer to the atomic masses in the periodic table inside the front cover of this textbook. State the mass of Avogadro s number of atoms for each of
More informationOther Stoich Calculations A. mole mass (mass mole) calculations. GIVEN mol A x CE mol B. PT g A CE mol A MOLE MASS :
Chem. I Notes Ch. 12, part 2 Using Moles NOTE: Vocabulary terms are in boldface and underlined. Supporting details are in italics. 1 MOLE = 6.02 x 10 23 representative particles (representative particles
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 informationChemical Equations & Stoichiometry
Chemical Equations & Stoichiometry Chapter Goals Balance equations for simple chemical reactions. Perform stoichiometry calculations using balanced chemical equations. Understand the meaning of the term
More informationUnit 7A  The Mole. We Need to Count atoms. The Mole and Molar Mass
Unit 7A  The Mole The Mole and Molar Mass We Need to Count atoms Airbags are inflated by a chemical reaction: electrical 2 NaN 3 (s) 3 N 2 (g) + 2 Na(s) decomposition Each airbag needs the right amount
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 informationFormulas, Equations and Moles
Chapter 3 Formulas, Equations and Moles Interpreting Chemical Equations You can interpret a balanced chemical equation in many ways. On a microscopic level, two molecules of H 2 react with one molecule
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 informationMultiple Choice questions (one answer correct)
Mole Concept Multiple Choice questions (one answer correct) (1) Avogadro s number represents the number of atoms in (a) 12g of C 12 (b) 320g of sulphur (c) 32g of oxygen (d) 12.7g of iodine (2) The number
More informationChapter 4. Chemical Composition. Chapter 4 Topics H 2 S. 4.1 Mole Quantities. The Mole Scale. Molar Mass The Mass of 1 Mole
Chapter 4 Chemical Composition Chapter 4 Topics 1. Mole Quantities 2. Moles, Masses, and Particles 3. Determining Empirical Formulas 4. Chemical Composition of Solutions Copyright The McGrawHill Companies,
More informationCHAPTER 8: CHEMICAL COMPOSITION
CHAPTER 8: CHEMICAL COMPOSITION Active Learning: 14, 68, 12, 1825; EndofChapter Problems: 34, 982, 8485, 8792, 94104, 107109, 111, 113, 119, 125126 8.2 ATOMIC MASSES: COUNTING ATOMS BY WEIGHING
More informationStoichiometry. Lecture Examples Answer Key
Stoichiometry Lecture Examples Answer Key Ex. 1 Balance the following chemical equations: 3 NaBr + 1 H 3 PO 4 3 HBr + 1 Na 3 PO 4 2 C 3 H 5 N 3 O 9 6 CO 2 + 3 N 2 + 5 H 2 O + 9 O 2 2 Ca(OH) 2 + 2 SO 2
More informationHOMEWORK 4A. Definitions. OxidationReduction Reactions. Questions
HOMEWORK 4A OxidationReduction Reactions 1. Indicate whether a reaction will occur or not in each of following. Wtiring a balcnced equation is not necessary. (a) Magnesium metal is added to hydrochloric
More informationChapter Three: STOICHIOMETRY
p70 Chapter Three: STOICHIOMETRY Contents p76 Stoichiometry  The study of quantities of materials consumed and produced in chemical reactions. p70 31 Counting by Weighing 32 Atomic Masses p78 Mass Mass
More informationLiquid phase. Balance equation Moles A Stoic. coefficient. Aqueous phase
STOICHIOMETRY Objective The purpose of this exercise is to give you some practice on some Stoichiometry calculations. Discussion The molecular mass of a compound is the sum of the atomic masses of all
More informationElement of same atomic number, but different atomic mass o Example: Hydrogen
Atomic mass: p + = protons; e  = electrons; n 0 = neutrons p + + n 0 = atomic mass o For carbon12, 6p + + 6n 0 = atomic mass of 12.0 o For chlorine35, 17p + + 18n 0 = atomic mass of 35.0 atomic mass
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 informationstoichiometry = the numerical relationships between chemical amounts in a reaction.
1 REACTIONS AND YIELD ANSWERS stoichiometry = the numerical relationships between chemical amounts in a reaction. 2C 8 H 18 (l) + 25O 2 16CO 2 (g) + 18H 2 O(g) From the equation, 16 moles of CO 2 (a greenhouse
More informationChemistry 65 Chapter 6 THE MOLE CONCEPT
THE MOLE CONCEPT Chemists find it more convenient to use mass relationships in the laboratory, while chemical reactions depend on the number of atoms present. In order to relate the mass and number of
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. 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 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 informationMultiple Choice Identify the letter of the choice that best completes the statement or answers the question.
Introduction to Chemistry Exam 2 Practice Problems 1 Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1.Atoms consist principally of what three
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 informationChemistry B11 Chapter 4 Chemical reactions
Chemistry B11 Chapter 4 Chemical reactions Chemical reactions are classified into five groups: A + B AB Synthesis reactions (Combination) H + O H O AB A + B Decomposition reactions (Analysis) NaCl Na +Cl
More informationThe Mole Concept. A. Atomic Masses and Avogadro s Hypothesis
The Mole Concept A. Atomic Masses and Avogadro s Hypothesis 1. We have learned that compounds are made up of two or more different elements and that elements are composed of atoms. Therefore, compounds
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 informationPART I: MULTIPLE CHOICE (30 multiple choice questions. Each multiple choice question is worth 2 points)
CHEMISTRY 12307 Midterm #1 Answer key October 14, 2010 Statistics: Average: 74 p (74%); Highest: 97 p (95%); Lowest: 33 p (33%) Number of students performing at or above average: 67 (57%) Number of students
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 informationCHEM 105 HOUR EXAM III 28OCT99. = 163 kj/mole determine H f 0 for Ni(CO) 4 (g) = 260 kj/mole determine H f 0 for Cr(CO) 6 (g)
CHEM 15 HOUR EXAM III 28OCT99 NAME (please print) 1. a. given: Ni (s) + 4 CO (g) = Ni(CO) 4 (g) H Rxn = 163 k/mole determine H f for Ni(CO) 4 (g) b. given: Cr (s) + 6 CO (g) = Cr(CO) 6 (g) H Rxn = 26
More informationFrom the book (10, 12, 16, 18, 22, 24 52, 54, 56, 58, 62, 64, 66, 68, 74, 76, 78, 80, 82, 86, 88, 90, 92, 106 and 116)
Chem 112 Solutions From the book (10, 12, 16, 18, 22, 24 52, 54, 56, 58, 62, 64, 66, 68, 74, 76, 78, 80, 82, 86, 88, 90, 92, 106 and 116) 1. Which of the following compounds are nonelectrolytes? A. NaF
More information2. ATOMIC, MOLECULAR AND EQUIVALENT MASSES
2. ATOMIC, MOLECULAR AND EQUIVALENT MASSES INTRODUCTION: EQUIVALENT WEIGHT Since hydrogen is the lightest of all elements, it was chosen as a standard for determination of equivalent weights. On this basis,
More informationChapter 1 The Atomic Nature of Matter
Chapter 1 The Atomic Nature of Matter 6. Substances that cannot be decomposed into two or more simpler substances by chemical means are called a. pure substances. b. compounds. c. molecules. d. elements.
More informationSolution a homogeneous mixture = A solvent + solute(s) Aqueous solution water is the solvent
Solution a homogeneous mixture = A solvent + solute(s) Aqueous solution water is the solvent Water a polar solvent: dissolves most ionic compounds as well as many molecular compounds Aqueous solution:
More informationCHAPTER 3 COMPOUNDS AND MOLECULES
Chapter 3 Compounds and Molecules Page 1 CHAPTER 3 COMPOUNDS AND MOLECULES 31. Octane, a component of gasoline, has eight carbon atoms and eighteen hydrogen atoms per molecule. Its formula is written
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 informationAtomic mass is the mass of an atom in atomic mass units (amu)
Micro World atoms & molecules Laboratory scale measurements Atomic mass is the mass of an atom in atomic mass units (amu) By definition: 1 atom 12 C weighs 12 amu On this scale 1 H = 1.008 amu 16 O = 16.00
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 informationChapter 6 OxidationReduction Reactions. Section 6.1 2. Which one of the statements below is true concerning an oxidationreduction reaction?
Chapter 6 OxidationReduction Reactions 1. Oxidation is defined as a. gain of a proton b. loss of a proton c. gain of an electron! d. loss of an electron e. capture of an electron by a neutron 2. Which
More informationName Date Class CHEMICAL QUANTITIES. SECTION 10.1 THE MOLE: A MEASUREMENT OF MATTER (pages 287 296)
Name Date Class 10 CHEMICAL QUANTITIES SECTION 10.1 THE MOLE: A MEASUREMENT OF MATTER (pages 287 296) This section defines the mole and explains how the mole is used to measure matter. It also teaches
More information1. When the following equation is balanced, the coefficient of Al is. Al (s) + H 2 O (l)? Al(OH) 3 (s) + H 2 (g)
1. When the following equation is balanced, the coefficient of Al is. Al (s) + H 2 O (l)? Al(OH) (s) + H 2 (g) A) 1 B) 2 C) 4 D) 5 E) Al (s) + H 2 O (l)? Al(OH) (s) + H 2 (g) Al (s) + H 2 O (l)? Al(OH)
More informationLecture Notes Chemistry E1. Chapter 3
Lecture Notes Chemistry E1 Chapter 3 http://inserbia.info/news/wpcontent/uploads/2013/05/tamiflu.jpg http://nutsforhealthcare.files.wordpress.com/2013/01/tamiflumoa.jpg The Mole A mole is a certain
More informationCHAPTER 12 GASES AND THEIR BEHAVIOR
Chapter 12 Gases and Their Behavior Page 1 CHAPTER 12 GASES AND THEIR BEHAVIOR 121. Which of the following represents the largest gas pressure? (a) 1.0 atm (b) 1.0 mm Hg (c) 1.0 Pa (d) 1.0 KPa 122. Nitrogen
More informationChapter 1 The Atomic Nature of Matter: Selected Answersc for Practice Exam.
Chapter 1 The Atomic Nature of Matter: Selected Answersc for Practice Exam. MULTIPLE CHOICE 50. 5.80 g of dioxane (C 4 H 8 O 2 ) is how many moles of dioxane? 0.0658 mol 0.0707 mol 0.0725 mol d. 0.0804
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 informationStoichiometry. 1. The total number of moles represented by 20 grams of calcium carbonate is (1) 1; (2) 2; (3) 0.1; (4) 0.2.
Stoichiometry 1 The total number of moles represented by 20 grams of calcium carbonate is (1) 1; (2) 2; (3) 01; (4) 02 2 A 44 gram sample of a hydrate was heated until the water of hydration was driven
More informationChem 31 Fall 2002. Chapter 3. Stoichiometry: Calculations with Chemical Formulas and Equations. Writing and Balancing Chemical Equations
Chem 31 Fall 2002 Chapter 3 Stoichiometry: Calculations with Chemical Formulas and Equations Writing and Balancing Chemical Equations 1. Write Equation in Words you cannot write an equation unless you
More informationmidterm1, 2009 Name: Class: Date:
Class: Date: midterm1, 2009 Record your name on the top of this exam and on the scantron form. Record the test ID letter in the top right box of the scantron form. Record all of your answers on the scantron
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 informationChapter 4 Notes  Types of Chemical Reactions and Solution Chemistry
AP Chemistry A. Allan Chapter 4 Notes  Types of Chemical Reactions and Solution Chemistry 4.1 Water, the Common Solvent A. Structure of water 1. Oxygen's electronegativity is high (3.5) and hydrogen's
More informationName Date Class CHEMICAL QUANTITIES. SECTION 10.1 THE MOLE: A MEASUREMENT OF MATTER (pages 287 296)
10 CHEMICAL QUANTITIES SECTION 10.1 THE MOLE: A MEASUREMENT OF MATTER (pages 287 296) This section defines the mole and explains how the mole is used to measure matter. It also teaches you how to calculate
More informationThe Mole and Molar Mass
The Mole and Molar Mass 1 Molar mass is the mass of one mole of a substance. Molar mass is numerically equal to atomic mass, molecular mass, or formula mass. However the units of molar mass are g/mol.
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 informationReactions. Balancing Chemical Equations uses Law of conservation of mass: matter cannot be lost in any chemical reaction
Reactions Chapter 8 Combustion Decomposition Combination Chapter 9 Aqueous Reactions Exchange reactions (Metathesis) Formation of a precipitate Formation of a gas Formation of a week or nonelectrolyte
More informationCalculations with Chemical Reactions
Calculations with Chemical Reactions Calculations with chemical reactions require some background knowledge in basic chemistry concepts. Please, see the definitions from chemistry listed below: Atomic
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 informationPractice questions for Chapter 8
Practice questions for Chapter 8 2) How many atoms of nickel equal a mass of 58.69 g? (Refer to the Periodic Table.) A) 1 B) 28 C) 58.69 D) 59 E) 6.02 x 1023 Answer: E Section: 8.1 Avogadro's Number 6)
More informationChemistry I Exam 1 review
Chemistry I Exam 1 review Name: For the multiple choice problems, mark the correct answer on the scantron with the corresponding problem number. For the open ended problems, show your work on the test,
More information2008 SOL Test. Name: Score: 50 / 50 points (100%)
Name: Score: 50 / 50 points (100%) 2008 SOL Test Multiple Choice Identify the choice that best completes the statement or answers the question. C 1. Trial Concentration 1 0.971 M 2 0.982 M 3 1.02 M 4 0.971
More informationIntroduction to Chemistry
1 Copyright ç 1996 Richard Hochstim. All rights reserved. Terms of use. Introduction to Chemistry In Chemistry the word weight is commonly used in place of the more proper term mass. 1.1 Atoms, Ions, and
More informationTutorial 4 SOLUTION STOICHIOMETRY. Solution stoichiometry calculations involve chemical reactions taking place in solution.
T27 Tutorial 4 SOLUTION STOICHIOMETRY Solution stoichiometry calculations involve chemical reactions taking place in solution. Of the various methods of expressing solution concentration the most convenient
More informationMoles and Chemical Reactions. Moles and Chemical Reactions. Molar mass = 2 x 12.011 + 6 x 1.008 + 1 x15.999 = 46.069 g/mol
We have used the mole concept to calculate mass relationships in chemical formulas Molar mass of ethanol (C 2 H 5 OH)? Molar mass = 2 x 12.011 + 6 x 1.008 + 1 x15.999 = 46.069 g/mol Mass percentage of
More informationUnit 9 Stoichiometry Notes (The Mole Continues)
Unit 9 Stoichiometry Notes (The Mole Continues) is a big word for a process that chemist s use to calculate amounts in reactions. It makes use of the coefficient ratio set up by balanced reaction equations
More informationMoles. Moles. Moles. Moles. Balancing Eqns. Balancing. Balancing Eqns. Symbols Yields or Produces. Like a recipe:
Like a recipe: Balancing Eqns Reactants Products 2H 2 (g) + O 2 (g) 2H 2 O(l) coefficients subscripts Balancing Eqns Balancing Symbols (s) (l) (aq) (g) or Yields or Produces solid liquid (pure liquid)
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 informationColligative Properties
CH302 LaBrake and Vanden Bout Colligative Properties PROBLEM #1: Give the molecular formula, the van t hoff factor for the following Ionic Compounds as well as guess the solubility of the compounds. If
More informationProblems you need to KNOW to be successful in the upcoming AP Chemistry exam.
Problems you need to KNOW to be successful in the upcoming AP Chemistry exam. Problem 1 The formula and the molecular weight of an unknown hydrocarbon compound are to be determined by elemental analysis
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 informationAtomic Masses. Chapter 3. Stoichiometry. Chemical Stoichiometry. Mass and Moles of a Substance. Average Atomic Mass
Atomic Masses Chapter 3 Stoichiometry 1 atomic mass unit (amu) = 1/12 of the mass of a 12 C atom so one 12 C atom has a mass of 12 amu (exact number). From mass spectrometry: 13 C/ 12 C = 1.0836129 amu
More informationMOLES AND MOLE CALCULATIONS
35 MOLES ND MOLE CLCULTIONS INTRODUCTION The purpose of this section is to present some methods for calculating both how much of each reactant is used in a chemical reaction, and how much of each product
More information1 What is the angular momentum quantum number (l) value for the 3p sublevel? A 1
1 What is the angular momentum quantum number (l) value for the 3p sublevel? 1 2 3 4 ORRET: For the 3p sublevel, the principal quantum number (n) is 3 and the angular momentum quantum number (l) is 1.
More informationCHEMISTRY II FINAL EXAM REVIEW
Name Period CHEMISTRY II FINAL EXAM REVIEW Final Exam: approximately 75 multiple choice questions Ch 12: Stoichiometry Ch 5 & 6: Electron Configurations & Periodic Properties Ch 7 & 8: Bonding Ch 14: Gas
More informationCP Chemistry Review for Stoichiometry Test
CP Chemistry Review for Stoichiometry Test Stoichiometry Problems (one given reactant): 1. Make sure you have a balanced chemical equation 2. Convert to moles of the known substance. (Use the periodic
More informationName: Regents Chemistry Review Packet A
Name: Regents Chemistry Review Packet A 1. According to the modern model of the atom, the nucleus of an atom is surrounded by one or more A) electrons B) neutrons A) an alpha particle B) a beta particle
More informationMOLAR MASS AND MOLECULAR WEIGHT Themolar mass of a molecule is the sum of the atomic weights of all atoms in the molecule. Molar Mass.
Counting Atoms Mg burns in air (O 2 ) to produce white magnesium oxide, MgO. How can we figure out how much oxide is produced from a given mass of Mg? PROBLEM: If If 0.200 g of Mg is is burned, how much
More information602X10 21 602,000,000,000, 000,000,000,000 6.02X10 23. Pre AP Chemistry Chemical Quan44es: The Mole. Diatomic Elements
Pre AP Chemistry Chemical Quan44es: The Mole Mole SI unit of measurement that measures the amount of substance. A substance exists as representa9ve par9cles. Representa9ve par9cles can be atoms, molecules,
More informationMole Concept and Stoichiometry
1 Mole Concept and Stoichiometry Concept Mole Concept Introduction This is our common experience that when we go to market to buy something, a few things we always get in definite numbers. For example,
More informationChapter 5, Calculations and the Chemical Equation
1. How many iron atoms are present in one mole of iron? Ans. 6.02 1023 atoms 2. How many grams of sulfur are found in 0.150 mol of sulfur? [Use atomic weight: S, 32.06 amu] Ans. 4.81 g 3. How many moles
More informationAPPENDIX B: EXERCISES
BUILDING CHEMISTRY LABORATORY SESSIONS APPENDIX B: EXERCISES Molecular mass, the mole, and mass percent Relative atomic and molecular mass Relative atomic mass (A r ) is a constant that expresses the ratio
More information87 16 70 20 58 24 44 32 35 40 29 48 (a) graph Y versus X (b) graph Y versus 1/X
HOMEWORK 5A Barometer; Boyle s Law 1. The pressure of the first two gases below is determined with a manometer that is filled with mercury (density = 13.6 g/ml). The pressure of the last two gases below
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 informationMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Chapter 10 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) A gas at a pressure of 10.0 Pa exerts a force of N on an area of 5.5 m2. A) 1.8 B) 0.55
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 informationChemistry CA 2 Practice
hemistry 2 Practice Some questions (c) 2015 by Region 10 Educational Service enter. Some questions (c) 2015 by Progress Testing. Page 2 1 Which of the following is the mass in grams of 4.25 10³ mol of
More information