# Chapter 5, Calculations and the Chemical Equation

Save this PDF as:

Size: px
Start display at page:

## Transcription

1 1. How many iron atoms are present in one mole of iron? Ans atoms 2. How many grams of sulfur are found in mol of sulfur? [Use atomic weight: S, amu] Ans g 3. How many moles of sulfur are found in atoms of sulfur? [Use atomic weight: S, amu] Ans mol 4. How many atoms are present in a 7.31 g sample of copper? [Use atomic weight: Cu, amu] Ans atoms 5. What is the mass, in grams, of 1.79 mol of helium, the gas commonly used to fill party balloons and lighter-than-air ships? [Use atomic weight: He, 4.00 amu] Ans g 6. An iodine sample contains atoms of iodine. What is its mass in grams? [Use atomic weight: I, amu] Ans g 7. Give the symbol(s) needed to show the smallest unit of nitrogen as it is normally found in nature. Ans. N 2 8. When a solid compound is described as a "hydrate", what does this mean? he compound contains water molecules in its structure. 9. What is the difference in meaning between "2O" and "O 2 " when they occur in chemical equations? Ans. 2O means 2 separate atoms of oxygen, not combined in the form of a molecule. O 2 means a molecule of oxygen, i.e. two atoms bonded to each other molecules of a covalent compound is equal to how many moles of that compound? Ans. 1 mol 11. What is the mass, in grams, of one mole of diatomic hydrogen? [Use molar mass: H, 1.0 g/mol] Ans. 2.0 g 12. How many molecules of water are there in 5.00 mol of water? Ans molecules 13. If one atom of oxygen weighs amu, what will one mole of oxygen (O 2 ) weigh? Ans g General, Organic, and Biochemistry, 3/e Page 29

2 14. Dinitrogen monoxide or laughing gas (N 2 O) is used as a dental anesthetic and as an aerosol propellant. How many moles of N 2 O are present in 12.6 g of the compound? [Use atomic weights: N, amu, O, amu] Ans mol 15. Dinitrogen monoxide or laughing gas (N 2 O) is used as a dental anesthetic and as an aerosol propellant. How many molecules of N 2 O are present in 12.6 g of the compound? [Use atomic weights: N, amu, O, amu] Ans molecules 16. What law states that matter cannot be gained or lost during a chemical reaction? Ans. law of conservation of mass 17. What does the symbol "(aq)", often found in chemical equations, mean? he reactant or product to which this applies is aqueous, i.e. dissolved in water. 18. In chemical equations, what are the meanings of the symbols s, l and g, used in parentheses? Ans. s = solid; l = liquid; g = gas 19. Balance the following equation: Ca(s) + HCl(g) CaCl 2 (s) + H 2 (g) Ans. Ca(s) + 2HCl(g) CaCl 2 (s) + H 2 (g) 20. Balance the following equation: Mg(OH) 2 (s) + HCl(g) MgCl 2 (s) + H 2 O(l) Ans. Mg(OH) 2 (s) + 2HCl(g) MgCl 2 (s) + 2H 2 O(l) 21. Balance the following equation: Na(s) + Cl 2 (g) NaCl(s) Ans. 2Na(s) + Cl 2 (g) 2NaCl(s) 22. Balance the equation for the combustion of octane, a component of gasoline, using smallest whole number coefficients: C 8 H 18 (l) + O 2 (g) CO 2 (g) + H 2 O(l) Ans. 2C 8 H 18 (l) + 25O 2 (g) 16CO 2 (g) + 18H 2 O(l) 23. Balance the equation for the complete oxidation of glucose (C 6 H 12 O 6 ), an important metabolic process: C 6 H 12 O 6 (l) + O 2 (g) CO 2 (g) + H 2 O(l) Ans. C 6 H 12 O 6 (l) + 6O 2 (g) 6CO 2 (g) + 6H 2 O(l) 24. How many moles of hydrogen gas are needed to react with oxygen to form two moles of water? 2H 2 (g) + O 2 (g) 2H 2 O(l) Ans. 2 mol 25. How many moles of oxygen gas are needed to react with hydrogen to form one mole of water? 2H 2 (g) + O 2 (g) 2H 2 O(l) Ans. 0.5 mol General, Organic, and Biochemistry, 3/e Page 30

3 26. How many grams of sodium hydroxide will react with g of aqueous HCl? [Use formula weights: NaOH, amu; HCl, amu] NaOH(aq) + HCl(aq) NaCl(aq) + H 2 O(l) Ans g 27. Calculate the number of grams of oxygen that must react with g of C 3 H 8 to produce only carbon dioxide and water. [Use atomic weights: C, amu; H, 1.01 amu; O, amu] Ans g 28. Iron reacts with oxygen to form iron(iii) oxide (Fe 2 O 3 ). How many grams of product will be formed from 5.00 grams of Fe? [Use atomic weights: Fe, amu; O, amu] Ans g 29. Glucose (C 6 H 12 O 6 ) is an important energy-rich compound, produced by photosynthesis: 6CO 2 (g) + 6H 2 O(l) C 6 H 12 O 6 (l) + 6O 2 (g) What mass of glucose, in grams, can be produced from 2.61 mol of CO 2 and the necessary water? [Use atomic weights: H, 1.01 amu; C, 12.01; 0, 16.00] Ans g 30. Explain what is meant by the term "limiting reactant" in a chemical reaction. Ans. If the amount of one reactant at the start of reaction is less than that required to react completely with the other reactants, according to the balanced equation, it is the limiting reactant. 31. Magnesium hydroxide (Mg(OH) 2 ), as "Milk of Magnesia" can be used to neutralize excess stomach acid, represented by HCl(aq): Mg(OH) 2 (s) + 2HCl(aq) MgCl 2 (aq) + 2H 2 O(l) When 5.00 g each of Mg(OH) 2 and HCl are combined, which is the limiting reactant, and what mass of MgCl 2 can be produced? [Use atomic weights: H, 1.01 amu; O, amu; Mg, amu; Cl, amu] Ans. HCl is limiting reactant; 6.53 g of MgCl 2 can be produced. 32. To convert a given number of moles into the number of atoms, you would multiply by which of the following factors? Ans. A A atoms/1 mol B. 1 mol/ atoms C atoms/1 mol D. 1 mol/ atoms E. molar mass General, Organic, and Biochemistry, 3/e Page 31

4 33. To convert from a given mass in grams to the number of moles, you would multiply by which of the following factors? A. 1/Avogadro's number B. Avogadro's number/1 C. molar mass/l D. 1/molar mass E. Avogadro's number/molar mass 34. To convert from a given number of atoms to the number of moles, you would multiply by which of the following factors? A. Avogadro's number/1 B. 1/Avogadro's number C. 1/molar mass D. molar mass/1 E. Avogadro's number/molar mass 35. To convert from a given number of grams to the number of atoms, you would multiply by which of the following factors? A. Avogadro's number/1 B. 1/Avogadro's number C. 1/molar mass D. molar mass/1 E. Avogadro's number/molar mass Ans. E 36. The average mass of one atom of iron is amu. What is the mass of Avogadro's number of atoms? A centigrams B g C kg D atoms E formula units 37. What is the weight, in grams, of one mole of hydrogen atoms? [Use atomic weight: H, 1.01 amu] Ans. A A g B g C g D g E g General, Organic, and Biochemistry, 3/e Page 32

5 38. How many grams of sulfur make up 3.01 mol of sulfur? [Use atomic weight: S, amu] A g B g C g D g E g Ans. E 39. How many moles are there in one ounce (28.4 g) of pure gold? [Use atomic weight: Au, amu] A mol B mol C mol D mol E mol Ans. C 40. How many atoms of sulfur are present in 155 g of sulfur? [Use atomic weight: S, amu] A atoms B atoms C atoms D atoms E atoms Ans. A 41. How many iron atoms are present in 3.01 mol of iron? A B C D E What is the formula weight of carbon dioxide? [Use atomic weights: C, amu; O, amu] Ans. C A amu B g C amu D g E mol General, Organic, and Biochemistry, 3/e Page 33

6 43. Aspirin is the common name for acetyl salicylic acid, C 9 H 8 O 4. A tablet has g of aspirin. How many moles is this? [Use formula weight: aspirin, amu] A mol B mol C mol D. 554 mol E mol 44. How many grams are there in mol of nicotine, a yellow liquid? [Use formula weight: nicotine, amu] A g B g C g D g E g Ans. C 45. How many molecules are there in mol of nicotine, a yellow liquid? A molecules B molecules C molecules D molecules E molecules 46. How many molecules are their in g of aspirin? [Use formula weight: aspirin, amu] A molecules B molecules C molecules D molecules E molecules Ans. A 47. What number will be found in front of "Al" when the following equation is balanced with smallest whole number coefficients? Al(s) + O 2 (g) Al 2 O 3 (s) A. 1 B. 2 C. 3 D. 4 E. 8 General, Organic, and Biochemistry, 3/e Page 34

7 48. How many moles of HCl can be formed when 2 mol of hydrogen gas react with chlorine? H 2 (g) + Cl 2 (g) HCl(g) (unbalanced) A. 0.5 mol B. 1 mol C. 2 mol D. 4 mol E. 8 mol 49. Which of the choices is the correctly balanced form of the following equation? C 6 H 14 (l) + O 2 (g) CO 2 (g) + H 2 O(l) A. C 6 H 14 (l) + 13O 2 (g) 6CO 2 (g) + 7H 2 O(l) B. C 6 H 14 (l) + 19O(g) 6CO 2 (g) + 7H 2 O(l) C. C 6 H 14 (l) + 19O 2 (g) 6CO 2 (g) + 7H 2 O(l) D. 2C 6 H 14 (l) + 19O 2 (g) 12CO 2 (g) + 14H 2 O(l) E. C 12 H 28 (l) + 38O(g) 12CO 2 (g) + 14H 2 O(l) 50. How many moles of hydrogen gas are needed to react with oxygen to form one mole of water? 2H 2 (g) + O 2 (g) 2H 2 O(l) A. 0.5 mol B. 1 mol C. 2 mol D. 4 mol E. 6 mol 51. Calculate the mass in grams of oxygen needed to react with mol of C 3 H 8 to form carbon dioxide and water. [Use atomic weight: O, amu] C 3 H 8 (g) + O 2 (g) CO 2 (g) + H 2 O(l) (unbalanced) A g B g C g D g E g Ans. E 52. Iron reacts with oxygen to form iron(iii) oxide (Fe 2 O 3 ). How many grams of product will be formed from g of Fe? [Use atomic weights: Fe, amu; O, amu] A g B g C g D g E g 53. Consider the hypothetical reaction: 3A 2 + 2B C + 2D How many moles of D can be formed from 5.0 mol of A 2 and excess B? A. 1.7 mol B. 3.3 mol C. 6.7 mol D. 7.5 mol E. 10. mol 54. T F One atomic mass unit is the same as one gram. 55. T F The smallest complete unit of iron is an atom of iron. General, Organic, and Biochemistry, 3/e Page 35

8 56. T F One mole of iron atoms contains molecules. 57. T F The formula weight of a compound is calculated by adding together the number of atoms that make it up. 58. T F Strictly speaking, it is incorrect to use the term "molecular weight" in referring to ionic compounds. 59. T F One mole of Ca 3 (PO 4 ) 2 contains atoms of calcium. 60. T F One mole of oxygen gas contains molecules. 61. T F The formula weight of water is equal to g. 62. T F If the atomic weight of hydrogen is 1.01 amu, a mole of H 2 will weigh 1.01 g. 63. T F One gram of gold (atomic weight 197 amu) contains more atoms than one gram of copper (atomic weight amu). 64. T F One mole of H 2 O contains a total of atoms. 65. T F The law of conservation of mass states that matter cannot be gained or lost during a chemical reaction. 66. T F The symbol, above or below the reaction arrow in an equation, indicates that heating is needed for the reaction to take place. 67. T F Counting the number of moles on both the reactant and product sides of an equation is the first step in balancing the equation. 68. T F In a correctly balanced equation, the number of moles of reactants and the number of moles of products may differ. 69. T F The term "dynamic equilibrium" is used to describe the condition of a reaction when one of the reactants has been completely used up. General, Organic, and Biochemistry, 3/e Page 36

9 70. T F 0.5 mol of oxygen gas can react with hydrogen gas to form 1.0 mol of water. General, Organic, and Biochemistry, 3/e Page 37

### Chemical 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

### Mole - Mass Relationships in Chemical Systems

Chapter 3: Stoichiometry Mole - Mass Relationships in Chemical Systems 3.1 The Mole 3.2 Determining the Formula of an Unknown Compound 3.3 Writing and Balancing Chemical Equations 3.4 Calculating the Amounts

### Chemical 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 +

### Chapter 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

### Chemical Reactions Chapter 8 Assignment & Problem Set

Chemical Reactions Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. Chemical Reactions 2 Study Guide: Things You Must Know Vocabulary (know the

### Molecular 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

### Chem 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

### Chapter 3 Chemical Reactions and Reaction Stoichiometry. 許富銀 ( Hsu Fu-Yin)

Chapter 3 Chemical Reactions and Reaction Stoichiometry 許富銀 ( Hsu Fu-Yin) 1 Stoichiometry The study of the numerical relationship between chemical quantities in a chemical reaction is called stoichiometry.

### Chapter 7: Chemical Reactions: An Introduction. Chemical Reactions, Equations and Balancing

Chapter 7: Chemical Reactions: An Introduction Chemical Reactions, Equations and Balancing Learning Target Chapter 7 Vocabulary 4 words 1. Chemical reaction 2. Reactant 3. Product 4. Coefficients balanced

### BALANCING 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

### IB Chemistry 1 Mole. One atom of C-12 has a mass of 12 amu. One mole of C-12 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 carbon-12 that were needed to make 12 g of carbon. 1 mole

### Ch. 9 Chemical Reactions

Ch. 9 Chemical Reactions I. Intro to Reactions (p. 282 285) I II III IV V Chemical Reaction Chemical change Atoms of one or more substances (reactants) are rearranged into new substances (products) Signs

### STOICHOMETRY UNIT Determine the mass of carbon present in a sample of glucose weighing 5.4 g.

PERCENTAGE COMPOSITION STOICHOMETRY UNIT 3 1. A sample of magnesium weighing 2.246 g burns in oxygen to form 3.724 g of magnesium oxide. What are the percentages of magnesium and oxygen in magnesium oxide?

### Name Class Date. Chapter: Chemical Equations and Reactions

Assessment Chapter Test A Chapter: Chemical Equations and Reactions In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question. 1. You

### Chapter 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

### Chemistry Stoichiometry. 45 points. Do not turn page until told to do so.

Chemistry 2010 Stoichiometry 45 points Do not turn page until told to do so. Stoichiometry Multiple Choice (Each worth 2 points) Identify the letter of the choice that best completes the statement or

### YIELD YIELD REACTANTS PRODUCTS

Balancing Chemical Equations A Chemical Equation: is a representation of a chemical reaction in terms of chemical formulas Example: 1. Word Description of a Chemical Reaction When methane gas (CH 4 ) burns

### W1 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

### 1. 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

### Name Class Date. Chapter: Chemical Equations and Reactions

Assessment Chapter Test B Chapter: Chemical Equations and Reactions PART I In the space provided, write the letter of the term or phrase that best completes each statement or best answers each question

### Chapter 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

### Balance the following equation: KClO 3 + C 12 H 22 O 11 KCl + CO 2 + H 2 O

Balance the following equation: KClO 3 + C 12 H 22 O 11 KCl + CO 2 + H 2 O Ans: 8 KClO 3 + C 12 H 22 O 11 8 KCl + 12 CO 2 + 11 H 2 O 3.2 Chemical Symbols at Different levels Chemical symbols represent

### The Mole Concept and Atoms

Copyright The McGraw-Hill 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

### SCIENCE NSPIRED. Open the TI-Nspire TM document Balancing_Chemical_Equations_Practice.tns.

Open the TI-Nspire TM document Balancing_Chemical_Equations_Practice.tns. In this activity you will use ChemBox feature of TI-Nspire TM technology to practice balancing chemical equations. Move to pages

### Moles. 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)

### 4. Aluminum chloride is 20.2% aluminum by mass. Calculate the mass of aluminum in a 35.0 gram sample of aluminum chloride.

1. Calculate the molecular mass of table sugar sucrose (C 12 H 22 O 11 ). A. 342.30 amu C. 320.05 amu B. 160.03 amu D. 171.15 amu 2. How many oxygen atoms are in 34.5 g of NaNO 3? A. 2.34 10 23 atoms C.

### Concept 1. The meaning and usefulness of the mole. The mole (or mol) represents a certain number of objects.

Chapter 3. Stoichiometry: Mole-Mass Relationships in Chemical Reactions Concept 1. The meaning and usefulness of the mole The mole (or mol) represents a certain number of objects. SI def.: the amount of

### Stoichiometry. 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

### Chapter 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

### Chapter 3 Mass Relationships in Chemical Reactions 國防醫學院生化學科王明芳老師

Chapter 3 Mass Relationships in Chemical Reactions 國防醫學院生化學科王明芳老師 2011-9-20 1 Balancing Chemical Equations A balanced chemical equation shows that the law of conservation of mass is adhered to. In a balanced

### Chemistry 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

### Chapter 3. Stoichiometry of Formulas and Equations

Chapter 3 Stoichiometry of Formulas and Equations Chapter 3 Outline: Mole - Mass Relationships in Chemical Systems 3.1 The Mole 3.2 Determining the Formula of an Unknown Compound 3.3 Writing and Balancing

### PERIODIC TABLE OF ELEMENTS. 4/23/14 Chapter 7: Chemical Reactions 1

PERIODIC TABLE OF ELEMENTS 4/23/14 Chapter 7: Chemical Reactions 1 CHAPTER 7: CHEMICAL REACTIONS 7.1 Describing Reactions 7.2 Types of Reactions 7.3 Energy Changes in Reactions 7.4 Reaction Rates 7.5 Equilibrium

### CHEM J-2 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 2014-J-2 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)

### MOLE 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

### Chapter 5. Chemical Reactions and Equations. Introduction. Chapter 5 Topics. 5.1 What is a Chemical Reaction

Introduction Chapter 5 Chemical Reactions and Equations Chemical reactions occur all around us. How do we make sense of these changes? What patterns can we find? 1 2 Copyright The McGraw-Hill Companies,

### Chapter 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.

### Calculations 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 10-24 g Atomic weight: Average mass of all isotopes of a given

### SCH3UI-02 Final Examination Review (Fall 2014)

SCH3UI-02 Final Examination Review (Fall 2014) 1. Chlorine has an atomic number of 17. Create a Bohr Rutherford diagram of a Cl-35 atom. To achieve a stable arrangement, is this atom most likely to gain

### Lecture 5 Outline. Derived from the Greek stoicheion ( element ) and metron ( measure )

Lecture 5 Outline 5.1 Stoichiometry,, the mole etc. 5.2 Chemical Equations 5.3 Molarity 5.4 Limiting reagents and yields 5.5 Reaction enthalpies and Gibbs free energy 5.6 Catalyst Lecture 5 Stoichiometry

### Chapter 3. Stoichiometry: Ratios of Combination. Insert picture from First page of chapter. Copyright McGraw-Hill 2009 1

Chapter 3 Insert picture from First page of chapter Stoichiometry: Ratios of Combination Copyright McGraw-Hill 2009 1 3.1 Molecular and Formula Masses Molecular mass - (molecular weight) The mass in amu

### 1. What is the molecular formula of a compound with the empirical formula PO and a gram-molecular mass of 284 grams?

Name: Tuesday, May 20, 2008 1. What is the molecular formula of a compound with the empirical formula PO and a gram-molecular mass of 284 grams? 2 5 1. P2O 5 3. P10O4 2. P5O 2 4. P4O10 2. Which substance

### Formulas, 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

### Stoichiometry. Unit Outline

3 Stoichiometry Unit Outline 3.1 The Mole and Molar Mass 3.2 Stoichiometry and Compound Formulas 3.3 Stoichiometry and Chemical Reactions 3.4 Stoichiometry and Limiting Reactants 3.5 Chemical Analysis

### Chapter 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 McGraw-Hill Companies,

### Lecture Notes Chemistry E-1. Chapter 3

Lecture Notes Chemistry E-1 Chapter 3 http://inserbia.info/news/wp-content/uploads/2013/05/tamiflu.jpg http://nutsforhealthcare.files.wordpress.com/2013/01/tamiflu-moa.jpg The Mole A mole is a certain

### STOICHIOMETRY STOICHIOMETRY. Measurements in Chemical Reactions. Mole-Mole Relationships. Mass-Mass Problem. Mole-Mole Relationships

STOICHIOMETRY STOICHIOMETRY The analysis of the quantities of substances in a chemical reaction. Stoichiometric calculations depend on the MOLE- MOLE relationships of substances. Measurements in Chemical

### Chemical bonding is the true difference between compounds and mixtures. Atomic elements:

Chapter 3 - Molecules, compounds, and chemical equations Elements and compounds Chemical bonding is the true difference between compounds and mixtures Atomic elements: Ionic bond: attraction of oppositely

### Writing and Balancing Chemical Equations

Name Writing and Balancing Chemical Equations Period When a substance undergoes a chemical reaction, chemical bonds are broken and new bonds are formed. This results in one or more new substances, often

### IB 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

### Molar Mass Worksheet Answer Key

Molar Mass Worksheet Answer Key Calculate the molar masses of the following chemicals: 1) Cl 2 71 g/mol 2) KOH 56.1 g/mol 3) BeCl 2 80 g/mol 4) FeCl 3 162.3 g/mol 5) BF 3 67.8 g/mol 6) CCl 2 F 2 121 g/mol

### Chemical 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 book-keeping Chemical Equations Chemical equations: Describe proportions

### Chapter 9. Answers to Questions

Chapter 9 Answers to Questions 1. Word equation: Silicon Tetrachloride + Water Silicon Dioxide + Hydrogen Chloride Formulas: Next, the chemical formulas are needed. As these are all covalent compounds,

### Moles. 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

### Mass 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

### Calculation 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

### Stoichiometry Chapter 9 Assignment & Problem Set

Stoichiometry Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. Stoichiometry 2 Study Guide: Things You Must Know Vocabulary (know the definition

### Chapter 8 Chemical Equations and Reactions

Chapter 8 Chemical Equations and Reactions 1 Section 8.1 Objectives: List 3 observations that suggest that a chemical reaction has taken place. List 3 requirements for a correctly written chemical reaction.

### Chapter 3 Stoichiometry of Formulas and Equations

3-1 Chapter 3 Stoichiometry of Formulas and Equations 3-2 Mole - Mass Relationships in Chemical Systems 3.1 The Mole 3.2 Determining the Formula of an Unknown Compound 3.3 Writing and Balancing Chemical

### MOLES 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

### Calculating Atoms, Ions, or Molecules Using Moles

TEKS REVIEW 8B Calculating Atoms, Ions, or Molecules Using Moles TEKS 8B READINESS Use the mole concept to calculate the number of atoms, ions, or molecules in a sample TEKS_TXT of material. Vocabulary

### TOPIC 8. CHEMICAL CALCULATIONS II: % composition, empirical formulas.

TOPIC 8. CHEMICAL CALCULATIONS II: % composition, empirical formulas. Percentage composition of elements in compounds. In Topic 1 it was stated that a given compound always has the same composition by

### The formation of a gas is evidence of. 1. A chemical change. 2. A physical change. 3. No change in energy 4. Both (1) and (2)

Chapter 8 Review The formation of a gas is evidence of 1. A chemical change. 2. A physical change. 3. No change in energy 4. Both (1) and (2) The formation of a gas is evidence of 1. A chemical change.

### CHAPTER 9. ANS: a. ANS: d. ANS: c. ANS: a. ANS: c

CHAPTER 9 1. Which one of the following is the acid in vinegar? a. acetic acid b. citric acid c. muriatic acid d. ascorbic acid 2. Which is a basic or alkaline substance? a. gastric fluid b. black coffee

### Chemical Reactions and Equations. Chapter 8

Chemical Reactions and Equations Chapter 8 Describing Chemical Reactions A chemical reaction is the process by which one or more substances are changed into different substances Reactants Products When

### Chapter 7: Chemical Equations. Name: Date: Period:

Chapter 7: Chemical Equations Name: Date: Period: 7-1 What is a chemical reaction? Read pages 232-237 a) Explain what a chemical reaction is. b) Distinguish between evidence that suggests a chemical reaction

### The 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

### Chemical Equations and Chemical Reactions. Chapter 8.1

Chemical Equations and Chemical Reactions Chapter 8.1 Objectives List observations that suggest that a chemical reaction has taken place List the requirements for a correctly written chemical equation.

### 4. Magnesium has three natural isotopes with the following masses and natural abundances:

Exercise #1 Atomic Masses 1. The average mass of pennies minted after 1982 is 2.50 g and the average mass of pennies minted before 1982 is 3.00 g. In a sample that contains 90.0% new and 10.0% old pennies,

### Types of Chemical Reactions

Why? Types of Chemical Reactions Do atoms rearrange in predictable patterns during chemical reactions? Recognizing patterns allows us to predict future behavior. Weather experts use patterns to predict

### CHAPTER 8 Chemical Equations and Reactions

CHAPTER 8 Chemical Equations and Reactions SECTION 1 Describing Chemical Reactions OBJECTIVES 1. List three observations that suggest that a chemical reaction has taken place. 2. List three requirements

### Balancing Chemical Equations

Balancing Chemical Equations Academic Success Center Science Tutoring Area Science Tutoring Area Law of Conservation of Mass Matter cannot be created nor destroyed Therefore the number of each type of

### Ch.4 Solutions. Solutions for Practice Problems p Consider the following reaction. 2H 2(g) + O 2(g) 2H 2 O (l)

Solutions for Practice Problems p. 114 Ch.4 Solutions 1. Consider the following reaction. 2H 2(g) + O 2(g) 2H 2 O (l) (a) Write the ratio of H 2 molecules: O 2 molecules: H 2 Omolecules. The ratio is given

### 7-5.5. Translate chemical symbols and the chemical formulas of common substances to show the component parts of the substances including:

7-5.5 Translate chemical symbols and the chemical formulas of common substances to show the component parts of the substances including: NaCl [salt], H 2 O [water], C 6 H 12 O 6 [simple sugar], O 2 [oxygen

### ATOMS. Multiple Choice Questions

Chapter 3 ATOMS AND MOLECULES Multiple Choice Questions 1. Which of the following correctly represents 360 g of water? (i) 2 moles of H 2 0 (ii) 20 moles of water (iii) 6.022 10 23 molecules of water (iv)

### Skeleton Equations equations describing a reaction using formulas. HCl(aq) + Zn(s) ZnCl 2 (aq) + H 2 (g)

10.1 Reactions and Equations Evidence of Chemical Reactions Chemical Reaction a process in which one or more substances are converted into new substances with different physical and chemical properties.

### Chapter 6 Oxidation-Reduction Reactions. Section 6.1 2. Which one of the statements below is true concerning an oxidation-reduction reaction?

Chapter 6 Oxidation-Reduction 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

### Formulas, 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

### Georgia Institute of Technology CHEM 1310 Fall Semester 2009 Recitation Assignment! Fundamental Principles and Terminology

The Fundamentals and Stoichiometry Recitation Worksheet Week of 25 August 2008. Fundamental Principles and Terminology Avogadro s Number: Used to represent the amount of a given atom as a basis for comparison

### Ch 8 Notes: Chemical Equations and Reactions

Name: Ch 8 Notes: Chemical Equations and Reactions I. Chemical Equations A properly written chemical equation can summarize any chemical change. The following requirements will help you write and read

### Do 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

### Honors Chemistry: Unit 6 Test Stoichiometry PRACTICE TEST ANSWER KEY Page 1. A chemical equation. (C-4.4)

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

### Chemical Reactions. Chemical Arithmetic

Chemical Reactions Chapter 6 Chemical Arithmetic Balancing Equations The mole Gram - mole conversions Mole - mole relationships in chemical equations Mass relationships in chemical equations Per cent yeilds

### Formulae, 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

### Chapter 6 Chemical Reactions: An Introduction

Chapter 6 Chemical Reactions: An Introduction Chemical Reactions Reactions involve chemical changes in matter that result in new substances. Reactions involve rearrangement and exchange of atoms to produce

### Study 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

### Test 4: Equations and Math of Equations Review

Name: Tuesday, November 27, 2007 Test 4: Equations and Math of Equations Review 1. Given the balanced equation: 2KClO 2KCl + 3O 3 2 Which type of reaction is represented by this equation? 1. synthesis

### Metals Topic Test. Part 1: Multiple Choice Choose the best alternative and indicate your response on the answer sheet

Metals Topic Test Part 1: Multiple Choice Choose the best alternative and indicate your response on the answer sheet 1. The chemical equation for the reaction between aluminium and oxygen is: 4Al (s) +

### Chemistry 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

### Atomic 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

### Chapter 8 - Chemical Equations and Reactions

Chapter 8 - Chemical Equations and Reactions 8-1 Describing Chemical Reactions I. Introduction A. Reactants 1. Original substances entering into a chemical rxn B. Products 1. The resulting substances from

### Chapter 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

### Chapter 5 Chemical Quantities and Reactions

Chapter 5 Chemical Quantities and Reactions 1 Avogadro's Number Small particles such as atoms, molecules, and ions are counted using the mole. 1 mole = 6.02 x 10 23 items Avogadro s number 602 000 000

### Problem Solving. Stoichiometry of Gases

Skills Worksheet Problem Solving Stoichiometry of Gases Now that you have worked with relationships among moles, mass, and volumes of gases, you can easily put these to work in stoichiometry calculations.

### Stoichiometry Review

Stoichiometry Review There are 20 problems in this review set. Answers, including problem set-up, can be found in the second half of this document. 1. N 2 (g) + 3H 2 (g) --------> 2NH 3 (g) a. nitrogen

### Sample Exercise 3.1 Interpreting and Balancing Chemical Equations

Sample Exercise 3.1 Interpreting and Balancing Chemical Equations The following diagram represents a chemical reaction in which the red spheres are oxygen atoms and the blue spheres are nitrogen atoms.

### Chapter 3 Stoichiometry

Chapter 3 Stoichiometry 3-1 Chapter 3 Stoichiometry In This Chapter As you have learned in previous chapters, much of chemistry involves using macroscopic measurements to deduce what happens between atoms