Chapter 11. Electrochemistry Oxidation and Reduction Reactions. Oxidation-Reduction Reactions. Oxidation-Reduction Reactions

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Chapter 11. Electrochemistry Oxidation and Reduction Reactions. Oxidation-Reduction Reactions. Oxidation-Reduction Reactions"

Transcription

1 Oxidation-Reduction Reactions Chapter 11 Electrochemistry Oxidation and Reduction Reactions An oxidation and reduction reaction occurs in both aqueous solutions and in reactions where substances are burned in the presence of oxygen gas, involves a transfer of electrons as the driving force of the chemical reaction. The reactants in these reactions will lose or gain electrons and change their charge as they form the products. The driving force of these chemical changes is electron transfer. 1 2 Oxidation-Reduction Reactions Oxidation- reduction reactions are a very important class of chemical reactions. They occur all around us and even within us. The bulk of the energy needed for the functioning of all living organisms, including humans, is obtained from food through oxidation-reduction processes. Such diverse phenomena as the electricity obtained from a battery to start a car, the use of natural gas to heat a home, iron rusting, and the functioning of antiseptic agents to kill or prevent the growth of bacteria all involve oxidationreduction reactions. The knowledge of this type of reaction is fundamental to understanding many biological and technological processes. 3 Oxidation-Reduction Reactions Historically, the word oxidation was first used to describe the reaction of a substance with oxygen. According to this historical definition, each of the following reactions involves oxidation: 4 Fe (s) + 3 O 2 (g) 2 Fe 2 O 3 (s) S (s) + O 2 (g) SO 2 (g) CH 4 (g) + 2 O 2 (g) CO 2 (g) + 2 H 2 O (g) The reactant on the far left (in bold) in each of these chemical equations is said to have been oxidized. 4 Oxidation-Reduction Reactions Oxidation-Reduction Reactions Originally, the term reduction referred to processes where oxygen was removed from a compound. A particularly common type of reduction reaction, according to the original definition, is the removal of oxygen from a metal oxide to produce free metal. CuO (s) + H 2 (g) Cu (s) + H 2 O (g) 2 Fe 2 O 3 (s) + 3 C (s) 4 Fe (s) + 3 CO 2 (g) The word reduction comes from the reduction in mass of the metal oxide; the free metal has less mass than the metal oxide. 5 Today the words oxidation and reduction are used in a much broader sense. Current definitions include the previous examples but also include reactions with numerous non-oxygen containing substances. Reactions that involve the transfer of electrons from one reactant to another reactant, regardless of the substances involve, are collectively called oxidation-reduction reactions (redox). 6

2 Oxidation-Reduction Reactions For all redox reactions, the reactants must lose electrons and gain electrons during the chemical process. Redox Reactions: OIL RIG OIL oxidation is loss of electrons (e.g., metals in salts) RIG reduction is gain of electrons (e.g., nonmetals in salts) The name given to the charge on an element, ion or element in a covalent bond is called the oxidation state or oxidation numbers. For example: Na + has an oxidation state of +1. F has an oxidation state of To determine what substance is oxidized and which is reduced, we must determine the original and final oxidation states of each substance during the chemical reaction. To determine the oxidation states of all elements in molecules or ionic compounds, it is necessary to follow a few rules. To assign oxidation numbers to elements in compounds, there are a few simple rules: 1. The oxidation number of any free, uncombined element is zero. Na (s), Mg (s), Cu (s), Fe (s) and Zn (s) 9 10 All naturally occurring diatomic molecules have zero oxidation states. Br 2 I 2 N 2 Cl 2 H 2 O 2 F 2 This makes sense there is no dipole (difference in Electronegativity) between the shared electrons in the diatomic molecules. Nonmetals, in their natural uncombined state, have zero oxidation states. E.g., P 4 (s) and S 8 (s) 2. For simple Group A binary ionic compounds (salts), the oxidation state is the charge of the element: Metals (Group I A, IIA, and IIIA) are assigned a positive oxidation state determined by the number of electrons the element has lost. Nonmetals (Group VA, VIA, VIIA) are assigned a negative oxidation state determined by the number of electrons the element has gained

3 Use the periodic table to help with assigning oxidation numbers to elements. a. IA metals have oxidation numbers of +1. b. IIA metals have oxidation numbers of +2. c. IIIA metals have oxidation numbers of +3. There are a few rare exceptions. d. VA elements have oxidation numbers of 3 in binary compounds with H, metals or NH 4+. e. VIA elements below O have oxidation numbers of 2 in binary compounds with H, metals or NH 4+. f. VIIA elements have oxidation numbers of 1 in binary compounds with H, metals or NH Groups IA metals IIA metals IIIA metals V nonmetals VI nonmetals Oxidation number Monoatomic Ions Li +, Na +, K +, Rb +, Cs + Mg 2+, Ca 2+, Sr 2+, Ba 2+ Al 3+, Ga 3+, In 3+ N 3, P 3, As 3, Sb 3, Bi 3 O, S, Se, Te 3. In the formula for any compound, the sum of the oxidation numbers of all elements in the compound is zero. Na 2 SO 4 = zero charge on formula unit In a polyatomic ion, the sum of the oxidation numbers of the constituent elements is equal to the charge on the ion. SO 4 2- =- 2on the ion. VII nonmetals 1 F, Cl, Br, I Fluorine has an oxidation number of 1 in its compounds. 5. Hydrogen, H, has an oxidation number of +1 unless it is combined with metals, where it has the oxidation number - 1. Examples LiH, BaH 2 6. Oxygen usually has the oxidation number 2. Exceptions: In peroxides O has oxidation number of 1. Examples: H 2 O 2, CaO 2, Na 2 O 2 In OF 2, O has oxidation number of +2. (Fluorine is the most electronegative element and has the greater share of electrons.) 17 18

4 For simple binary ionic compounds that are comprised of transition metals (with more than one possible oxidation state), the oxidation state of the metal is determined by balancing the charge: For our purpose, all transition metals in salts (except zinc and silver) have oxidation states that are determined by the balancing the charge of the anion. e.g. FeO vs. Fe 2 O 3-2 FeO Since the oxidation state of oxygen is 2 in the compound, the iron atom must have a charge of + 2 to give the formula unit an overall net charge of zero. x + (- 2) = 0 x = Fe 2 O 3 Since the oxidation state of oxygen is 2 in the compound and there are three oxygen atoms, the iron must have a charge of +3 to give the formula unit an overall net charge of zero. 2x + 3(- 2) = 0 x = + 3 Zinc always has an oxidation state of +2 when combined in a salt. ZnCl 2, ZnS, ZnSO 4, Zn 3 (PO 4 ) 2 Silver always has an oxidation state of +1 when combined in a salt. AgCl, Ag 2 O, Ag 2 SO 4, Ag 3 PO Example: Assign oxidation numbers to each element in the following compounds: NaNO 3 Na = +1 O = 2 N =? Calculate using rule (-2) + x = 0 x = +5 N = +5 K 2 Sn(OH) 6 K = +1 O = - 2 H = +1 Sn =? 2(+1) + 6(-2) + 6(+1) + x = 0 x = +4 Sn =

5 H 3 PO 4 H = +1 O = - 2 P =? P = +5 3(+1) + 4( 2) + x = 0 = + 5 SO 3 2- O = - 2 S =? S = +4 3(-2) + x = -2 x = HCO 3 Cr 2 O 7 2- O = - 2 H = +1 C =? O = 2 Cr =? C = ( 2) + x = 1 x = +4 Cr = +6 7( 2) + 2(x) = 2 x = Determine the oxidation number of the underlined element in FeSO 4. The oxidation state of iron must be +2 in order to balance the 2 of the sulfate ion. Fe = + 2 O = x + 4( 2) = 0 x = + 6 OR The oxidation state of sulfur can be determined by the sulfate ion: SO 4 x + 4( 2) = 2 x =

6 Determine the oxidation number of the underlined element in Mg(ClO 4 ) 2. OR Mg = + 2 O = x + 8( 2) = 0 x = + 7 ClO 4 x + 4( 2) = 1 Determine the oxidation number of the underlined element in CH 4. H = +1 (least electronegative element) C = 4 Determine the oxidation number of the underlined element in CO 2. O = 2 (most electronegative element) C = + 4 x = Determine the oxidation number of the underlined element in H 2 O. H = + 1 (the least electronegative element) O = 2 Determine the oxidation number of the underlined element in H 2 O 2. H = + 1 (the least electronegative element) O = 1 Oxidation Reduction Reactions: REDOX Oxidizing agents are those elements that cause loss of electrons (cause oxidation) oxidizing agents are reduced by gaining electrons. Reducing agents are those elements that give up electrons (cause reduction) reducing agents are oxidized by giving up electrons In redox reactions, the reactants transfer electrons oxidation and reduction occurs between the reactants Na (s) + Cl 2 (g) 2 NaCl (s) To determine the oxidizing agent and reducing agent, we can divide the reaction of the reactants into halfreactions: 0 +1 oxidation reaction: : 2 Na 2 Na+ + 2 e reducing agent 0 1 reduction reaction: : Cl e 2 Cl oxidizing agent 35 Since we cannot either create or destroy electrons, the numbers of electrons transferred in the reaction must be the same on both sides of the chemical equation: Fe (s) + 3 O 2 (g) 2 Fe 2 O 3 (s) 0 +3 oxidation reaction 4 Fe 4 Fe e 0 2 reduction reaction 3 O e 6 O reducing agent oxidizing agent 36

7 NaBr (aq) + Cl 2(l) 2 NaCl (aq) + Br 2(s) We can remove the spectator ion (Na + ) before we set up the half- reactions. oxidation reaction Br Br 2 + 2e reducing agent A more complicated redox reaction requires that we must identify what is oxidized and what is reduced by assigning oxidation states to all the elements in the reactants and products H 2 SO 4(aq) + 2 HI (g) SO 2(g) + I 2(s) + 2 H 2 O reduction reaction 0 1 Cl e 2 Cl oxidizing agent H 2 SO 4(aq) + 2 HI (g) SO 2(g) + I 2(s) + 2 H 2 O We must identify in the reaction which elements changed oxidation states. The oxidation state of hydrogen is the same on both sides of the equation, so it is not involved in transfer of electrons. The oxidation state of oxygen is the same on both sides of the equation, so it is not involved in transfer of electrons. The oxidation state of sulfur changed and the oxidation state of iodine changed. 1 0 oxidation reaction 2 I I e red agent reduction reaction SO e SO 2 ox agent It is not always obvious how to balance a redox equation. For these more complex oxidation- reduction reactions, we have a system by which to balance the equation by mass and by charge. The half- reaction method is useful in that it is the method that is used in electrolysis. Balance the equation as much as possible without the spectator ions. Set up half- reactions (oxidation and reduction) as we did in the previous reactions

8 Balance the half- reactions by the following rules: First, determine if the reaction has taken place in acidic (H + ) conditions or basic (OH ) conditions. The rules for balancing oxygen and hydrogen are different depending on whether the reaction takes place in acidic or basic solutions. The Half-Reaction Method Half reaction method rules: 1. Write the unbalanced reaction. 2. Break the reaction into 2 half reactions: One oxidation half-reaction and One reduction half-reaction Each reaction must have complete formulas for molecules and ions. 3. Mass balance each half reaction by adding appropriate stoichiometric coefficients The Half-Reaction Method 4. Charge balance the half reactions by adding appropriate numbers of electrons. Electrons will be products in the oxidation half-reaction. Electrons will be reactants in the reduction half-reaction. 5. Multiply each half reaction by a number to make the number of electrons in the oxidation half-reaction equal to the number of electrons reduction half-reaction. 6. Add the two half reactions. 7. Eliminate any common terms and reduce coefficients to smallest whole numbers. In acidic conditions: Balance the oxygen by adding H 2 O molecules to the opposite side of the equation. Balance the hydrogen by adding H+ to the opposite side of the equation Example: C (s) + HNO 3 (aq) CO 2 (g) + NO 2 (g) + H 2 O Set up the half- reactions: C CO e oxidation NO 3 + 1e NO 2 reduction Balance the oxygen by adding H 2 O to the opposite side. (One H 2 O for each oxygen) 2 H 2 O + C CO e NO 3 + 1e NO 2 + H 2 O Balance the hydrogen by adding H + to the opposite side. 2 H 2 O + C CO e + 4 H + 2 H + + NO 3 + 1e NO 2 + H 2 O 47 48

9 The number of e must be the same on both sides of the equation. Balance the charge by multiplying the half- reaction with the appropriate number to give the same number of electrons on both sides of the equation. 2 H 2 O + C CO e + 4 H + 4 (2 H + + NO 3 + 1e NO 2 + H 2 O) 2 H 2 O + C CO e + 4 H + 8 H NO e 4 NO H 2 O Cancel e, water, and H + from opposite sides of the equations, and sum the remaining reactants and products. 2 H 2 O + C CO e + 4 H H NO e 4 NO H 2 O. 4 H NO 3 + C 4 NO 2 + CO H 2 O Add the H + back to the NO 3 ions to complete the equation: 4 HNO 3 + C 4 NO 2 + CO H 2 O In basic conditions: Balance the oxygen by adding 2 OH molecules to the side that needs oxygen and adding one H 2 O to the other side. Balance the hydrogen by adding H 2 O to the side that needs hydrogen and adding one OH to the other side Example: In basic solution, hypochlorite ions (ClO ) oxidize chromite ions (CrO ) to chromate ions (CrO 4 ) and are reduced to chloride ions. Write a balanced net ionic equation for this reaction CrO + ClO CrO 4 + Cl Set up the half-reactions: CrO 2 CrO e oxidation ClO + 2 e Cl reduction Balance the oxygen by adding 2 OH to the opposite side. (2 OH for each oxygen) CrO + 4 OH CrO e ClO + 2 e Cl + 2 OH Balance the hydrogen by adding one H 2 O for every two OH - on the opposite side. CrO + 4 OH CrO H 2 O + 3 e H 2 O + ClO + 2 e Cl + 2 OH 53 54

10 Balance the charge by multiplying the half- reaction with the appropriate number to give the same number of electrons on both sides of the equation. 2 (CrO + 4 OH CrO H 2 O + 3 e ) 3 (H 2 O + ClO + 2 e Cl + 2 OH ) 2 CrO + 8 OH 2 CrO H 2 O + 6 e 3 H 2 O + 3 ClO + 6 e 3 Cl + 6 OH Add the two half reactions. Eliminate any common terms and reduce coefficients to smallest whole numbers CrO + 8 OH 2 CrO H 2 O + 6 e 3 H 2 O + 3 ClO + 6 e 3 Cl + 6 OH 2 CrO + 2 OH + 3 ClO - 2 CrO 4 + H 2 O + 3 Cl Stoichiometry of Redox Reactions It is possible in a few reactions that an element in the reactant is oxidized and it is also the element that is reduced. This is called a disproportionation oxidation-reducion reaction. Redox titrations: Titrations can be preformed to determine the presence of substances that are oxidized or reduced. In this procedure, the standard is a solution of a known oxidizing or reducing agent. Slide 25 p.148 Note that chlorine in the reactant is oxidized and also reduced during the reaction. We will do the half reactions in class Stoichiometry of Redox Reactions Stoichiometry of Redox Reactions Example. What volume of M KMnO 4 is required to oxidize 35.0 ml of M HCl? The balanced reaction is: 2 KMnO HCl 2 KCl+2 MnCl 2+ 5 Cl2+ 8 H2O ( )( ) 35 ml HCl M HCl = 5.25 mmol HCl ( ) mmol HCl mmol KMnO4 ( ) 2 mmol KMnO = 16 mmol HCl 1 ml mmol KMnO4 = 3.28 ml mmol KMnO

11 Stoichiometry of Redox Reactions End of Chapter 11 Example. A volume of 40.0 ml of iron (II) sulfate is oxidized to iron (III) by 20.0 ml of M potassium dichromate solution. What is the concentration of the iron (II) sulfate solution? We will solve this problem and others during class. 61

1. 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) 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 information

Chemistry Post-Enrolment Worksheet

Chemistry Post-Enrolment Worksheet Name: Chemistry Post-Enrolment Worksheet The purpose of this worksheet is to get you to recap some of the fundamental concepts that you studied at GCSE and introduce some of the concepts that will be part

More information

Answers and Solutions to Text Problems

Answers and Solutions to Text Problems Chapter 7 Answers and Solutions 7 Answers and Solutions to Text Problems 7.1 A mole is the amount of a substance that contains 6.02 x 10 23 items. For example, one mole of water contains 6.02 10 23 molecules

More information

W1 WORKSHOP ON STOICHIOMETRY

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

More information

PART I: MULTIPLE CHOICE (30 multiple choice questions. Each multiple choice question is worth 2 points)

PART I: MULTIPLE CHOICE (30 multiple choice questions. Each multiple choice question is worth 2 points) CHEMISTRY 123-07 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 information

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 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 information

Moles. Moles. Moles. Moles. Balancing Eqns. Balancing. Balancing Eqns. Symbols Yields or Produces. Like a recipe:

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)

More information

UNIT (4) CALCULATIONS AND CHEMICAL REACTIONS

UNIT (4) CALCULATIONS AND CHEMICAL REACTIONS UNIT (4) CALCULATIONS AND CHEMICAL REACTIONS 4.1 Formula Masses Recall that the decimal number written under the symbol of the element in the periodic table is the atomic mass of the element. 1 7 8 12

More information

Chapter 5 Chemical Quantities and Reactions. Collection Terms. 5.1 The Mole. A Mole of a Compound. A Mole of Atoms.

Chapter 5 Chemical Quantities and Reactions. Collection Terms. 5.1 The Mole. A Mole of a Compound. A Mole of Atoms. Chapter 5 Chemical Quantities and Reactions 5.1 The Mole Collection Terms A collection term states a specific number of items. 1 dozen donuts = 12 donuts 1 ream of paper = 500 sheets 1 case = 24 cans 1

More information

English already has many collective nouns for fixed, given numbers of objects. Some of the more common collective nouns are shown in Table 7.1.

English already has many collective nouns for fixed, given numbers of objects. Some of the more common collective nouns are shown in Table 7.1. 96 Chapter 7: Calculations with Chemical Formulas and Chemical Reactions Chemical reactions are written showing a few individual atoms or molecules reacting to form a few atoms or molecules of products.

More information

Name: Class: Date: 2 4 (aq)

Name: Class: Date: 2 4 (aq) Name: Class: Date: Unit 4 Practice Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1) The balanced molecular equation for complete neutralization of

More information

Chapter 3 Stoichiometry

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

More information

Chapter 3 Mass Relationships in Chemical Reactions

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

More information

Calculations and Chemical Equations. Example: Hydrogen atomic weight = 1.008 amu Carbon atomic weight = 12.001 amu

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

More information

CHEM 120 Online: Chapter 6 Sample problems Date: 2. Which of the following compounds has the largest formula mass? A) H2O B) NH3 C) CO D) BeH2

CHEM 120 Online: Chapter 6 Sample problems Date: 2. Which of the following compounds has the largest formula mass? A) H2O B) NH3 C) CO D) BeH2 CHEM 120 Online: Chapter 6 Sample problems Date: 1. To determine the formula mass of a compound you should A) add up the atomic masses of all the atoms present. B) add up the atomic masses of all the atoms

More information

SCH 4C1 Unit 2 Problem Set Questions taken from Frank Mustoe et all, "Chemistry 11", McGraw-Hill Ryerson, 2001

SCH 4C1 Unit 2 Problem Set Questions taken from Frank Mustoe et all, Chemistry 11, McGraw-Hill Ryerson, 2001 SCH 4C1 Unit 2 Problem Set Questions taken from Frank Mustoe et all, "Chemistry 11", McGraw-Hill 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 information

Candidate Style Answer

Candidate Style Answer Candidate Style Answer Chemistry A Unit F321 Atoms, Bonds and Groups High banded response This Support Material booklet is designed to accompany the OCR GCE Chemistry A Specimen Paper F321 for teaching

More information

I N V E S T I C E D O R O Z V O J E V Z D Ě L Á V Á N Í CHEMICAL REACTIONS

I N V E S T I C E D O R O Z V O J E V Z D Ě L Á V Á N Í CHEMICAL REACTIONS Chemical reaction = process during which original substances change to new substances, reactants turn to... The bonds of reactants... and new bonds are... The classification of reactions: 1. Classification

More information

STOICHIOMETRY UNIT 1 LEARNING OUTCOMES. At the end of this unit students will be expected to:

STOICHIOMETRY UNIT 1 LEARNING OUTCOMES. At the end of this unit students will be expected to: STOICHIOMETRY LEARNING OUTCOMES At the end of this unit students will be expected to: UNIT 1 THE MOLE AND MOLAR MASS define molar mass and perform mole-mass inter-conversions for pure substances explain

More information

Formulas, Equations and Moles

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

More information

Chapter 3: Stoichiometry

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

More information

Amount of Substance. http://www.avogadro.co.uk/definitions/elemcompmix.htm

Amount of Substance. http://www.avogadro.co.uk/definitions/elemcompmix.htm Page 1 of 14 Amount of Substance Key terms in this chapter are: Element Compound Mixture Atom Molecule Ion Relative Atomic Mass Avogadro constant Mole Isotope Relative Isotopic Mass Relative Molecular

More information

Chapter 1 The Atomic Nature of Matter

Chapter 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 information

Study Guide For Chapter 7

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

More information

CHAPTER 3 Calculations with Chemical Formulas and Equations. atoms in a FORMULA UNIT

CHAPTER 3 Calculations with Chemical Formulas and Equations. atoms in a FORMULA UNIT CHAPTER 3 Calculations with Chemical Formulas and Equations MOLECULAR WEIGHT (M. W.) Sum of the Atomic Weights of all atoms in a MOLECULE of a substance. FORMULA WEIGHT (F. W.) Sum of the atomic Weights

More information

Calculating Atoms, Ions, or Molecules Using Moles

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

More information

Chapter 1: Moles and equations. Learning outcomes. you should be able to:

Chapter 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 information

MOLES AND MOLE CALCULATIONS

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

More information

Mole Notes.notebook. October 29, 2014

Mole 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 information

THE MOLE / COUNTING IN CHEMISTRY

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 information

Stoichiometry. Unit Outline

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

More information

Chem 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 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 information

Stoichiometry. Lecture Examples Answer Key

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

More information

Number of moles of solute = Concentration (mol. L ) x Volume of solution (litres) or n = C x V

Number of moles of solute = Concentration (mol. L ) x Volume of solution (litres) or n = C x V 44 CALCULATIONS INVOLVING SOLUTIONS INTRODUCTION AND DEFINITIONS Many chemical reactions take place in aqueous (water) solution. Quantities of such solutions are measured as volumes, while the amounts

More information

Chemistry Final Study Guide

Chemistry Final Study Guide Name: Class: Date: Chemistry Final Study Guide Multiple Choice Identify the choice that best completes the statement or answers the question. 1. The electrons involved in the formation of a covalent bond

More information

Tuesday, November 27, 2012 Expectations:

Tuesday, November 27, 2012 Expectations: Tuesday, November 27, 2012 Expectations: Sit in assigned seat Get out Folder, Notebook, Periodic Table Have out: Spiral (notes), Learning Target Log (new) No Backpacks on tables Listen/Pay Attention Learning

More information

602X10 21 602,000,000,000, 000,000,000,000 6.02X10 23. Pre- AP Chemistry Chemical Quan44es: The Mole. Diatomic Elements

602X10 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 information

The Mole. Chapter 2. Solutions for Practice Problems

The Mole. Chapter 2. Solutions for Practice Problems Chapter 2 The Mole Note to teacher: You will notice that there are two different formats for the Sample Problems in the student textbook. Where appropriate, the Sample Problem contains the full set of

More information

ATOMS. Multiple Choice Questions

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)

More information

Tutorial 2 FORMULAS, PERCENTAGE COMPOSITION, AND THE MOLE

Tutorial 2 FORMULAS, PERCENTAGE COMPOSITION, AND THE MOLE T-6 Tutorial 2 FORMULAS, PERCENTAGE COMPOSITION, AND THE MOLE FORMULAS: A chemical formula shows the elemental composition of a substance: the chemical symbols show what elements are present and the numerical

More information

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

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

More information

Lecture 5, The Mole. What is a mole?

Lecture 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 10-24 g How many 12 C atoms weigh 12 g?

More information

Chapter 6. Oxidation- Review Skills

Chapter 6. Oxidation- Review Skills Chapter 6 Oxidation-Reduction Reactions n many important chemical reactions, electrons are transferred from atom to atom. We are surrounded by these reactions, commonly called oxidation reduction (or redox)

More information

1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436 #1, 7, 8, 11

1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436 #1, 7, 8, 11 SCH3U- R.H.KING ACADEMY SOLUTION & ACID/BASE WORKSHEET Name: The importance of water - MAKING CONNECTION READING 1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436

More information

Sample Exercise 3.1 Interpreting and Balancing Chemical Equations

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.

More information

Calculation of Molar Masses. Molar Mass. Solutions. Solutions

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

More information

Chapter 6 Chemical Calculations

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

More information

Part One: Mass and Moles of Substance. Molecular Mass = sum of the Atomic Masses in a molecule

Part 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 information

Woods Chem-1 Lec-02 10-1 Atoms, Ions, Mole (std) Page 1 ATOMIC THEORY, MOLECULES, & IONS

Woods Chem-1 Lec-02 10-1 Atoms, Ions, Mole (std) Page 1 ATOMIC THEORY, MOLECULES, & IONS Woods Chem-1 Lec-02 10-1 Atoms, Ions, Mole (std) Page 1 ATOMIC THEORY, MOLECULES, & IONS Proton: A positively charged particle in the nucleus Atomic Number: We differentiate all elements by their number

More information

Test Review Periodic Trends and The Mole

Test Review Periodic Trends and The Mole Test Review Periodic Trends and The Mole The Mole SHOW ALL WORK ON YOUR OWN PAPER FOR CREDIT!! 1 2 (NH42SO2 %N 24.1 %H 6.9 %S 27.6 %O 41.3 % Al %C 35.3 %H 4.4 %O 47.1 Al(C2H3O23 13.2 3 How many moles are

More information

AP Chemistry 2006 Free-Response Questions

AP Chemistry 2006 Free-Response Questions AP Chemistry 006 Free-Response Questions The College Board: Connecting Students to College Success The College Board is a not-for-profit membership association whose mission is to connect students to college

More information

MOLECULAR MASS AND FORMULA MASS

MOLECULAR MASS AND FORMULA MASS 1 MOLECULAR MASS AND FORMULA MASS Molecular mass = sum of the atomic weights of all atoms in the molecule. Formula mass = sum of the atomic weights of all atoms in the formula unit. 2 MOLECULAR MASS AND

More information

The Mole Concept. The Mole. Masses of molecules

The Mole Concept. The Mole. Masses of molecules The Mole Concept Ron Robertson r2 c:\files\courses\1110-20\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 information

Figure 1. A voltaic cell Cu,Cu 2+ Ag +, Ag. gas is, by convention, assigned a reduction potential of 0.00 V.

Figure 1. A voltaic cell Cu,Cu 2+ Ag +, Ag. gas is, by convention, assigned a reduction potential of 0.00 V. Voltaic Cells Introduction In this lab you will first prepare a set of simple standard half-cells and then measure the voltage between the half-cells with a voltmeter. From this data you will be able to

More information

Acids and Bases. Chapter 16

Acids and Bases. Chapter 16 Acids and Bases Chapter 16 The Arrhenius Model An acid is any substance that produces hydrogen ions, H +, in an aqueous solution. Example: when hydrogen chloride gas is dissolved in water, the following

More information

Atomic mass is the mass of an atom in atomic mass units (amu)

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

More information

Moles, Molecules, and Grams Worksheet Answer Key

Moles, Molecules, and Grams Worksheet Answer Key Moles, Molecules, and Grams Worksheet Answer Key 1) How many are there in 24 grams of FeF 3? 1.28 x 10 23 2) How many are there in 450 grams of Na 2 SO 4? 1.91 x 10 24 3) How many grams are there in 2.3

More information

MASS RELATIONSHIPS IN CHEMICAL REACTIONS

MASS RELATIONSHIPS IN CHEMICAL REACTIONS MASS RELATIONSHIPS IN CHEMICAL REACTIONS 1. The mole, Avogadro s number and molar mass of an element. Molecular mass (molecular weight) 3. Percent composition of compounds 4. Empirical and Molecular formulas

More information

Solutions to Supplementary Check for Understanding Problems

Solutions to Supplementary Check for Understanding Problems Chapter 5 s to Supplementary Check for Understanding Problems Moles and Molar Mass 1. Indicate the appropriate quantity for each of the following. a) A mole of N atoms contains atoms. b) A mole of N molecules

More information

Bonding in Elements and Compounds. Covalent

Bonding in Elements and Compounds. Covalent Bonding in Elements and Compounds Structure of solids, liquids and gases Types of bonding between atoms and molecules Ionic Covalent Metallic Many compounds between metals & nonmetals (salts), e.g. Na,

More information

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 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,

More information

Composition of nucleus. Priority Vocabulary: Electron, Proton, Neutron, Nucleus, Isotopes, Atomic Number, Atomic Mass, Element, Electron Shell,

Composition of nucleus. Priority Vocabulary: Electron, Proton, Neutron, Nucleus, Isotopes, Atomic Number, Atomic Mass, Element, Electron Shell, Lake County, Lakeview, 9 th grade, Physical Science, Brent Starr Standard: H1P1 Explain how atomic structure is related to the properties of elements and their position in the Periodic Table. Explain how

More information

Lecture Topics Atomic weight, Mole, Molecular Mass, Derivation of Formulas, Percent Composition

Lecture Topics Atomic weight, Mole, Molecular Mass, Derivation of Formulas, Percent Composition Mole Calculations Chemical Equations and Stoichiometry Lecture Topics Atomic weight, Mole, Molecular Mass, Derivation of Formulas, Percent Composition Chemical Equations and Problems Based on Miscellaneous

More information

Bonds. Bond Length. Forces that hold groups of atoms together and make them function as a unit. Bond Energy. Chapter 8. Bonding: General Concepts

Bonds. Bond Length. Forces that hold groups of atoms together and make them function as a unit. Bond Energy. Chapter 8. Bonding: General Concepts Bonds hapter 8 Bonding: General oncepts Forces that hold groups of atoms together and make them function as a unit. Bond Energy Bond Length It is the energy required to break a bond. The distance where

More information

Chemistry 65 Chapter 6 THE MOLE CONCEPT

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

More information

Soil Chemistry Ch. 2. Chemical Principles As Applied to Soils

Soil Chemistry Ch. 2. Chemical Principles As Applied to Soils Chemical Principles As Applied to Soils I. Chemical units a. Moles and Avogadro s number The numbers of atoms, ions or molecules are important in chemical reactions because the number, rather than mass

More information

Sugar or Salt? Ionic and Covalent Bonds

Sugar or Salt? Ionic and Covalent Bonds Lab 11 Sugar or Salt? Ionic and Covalent Bonds TN Standard 2.1: The student will investigate chemical bonding. Have you ever accidentally used salt instead of sugar? D rinking tea that has been sweetened

More information

7. 1.00 atm = 760 torr = 760 mm Hg = 101.325 kpa = 14.70 psi. = 0.446 atm. = 0.993 atm. = 107 kpa 760 torr 1 atm 760 mm Hg = 790.

7. 1.00 atm = 760 torr = 760 mm Hg = 101.325 kpa = 14.70 psi. = 0.446 atm. = 0.993 atm. = 107 kpa 760 torr 1 atm 760 mm Hg = 790. CHATER 3. The atmosphere is a homogeneous mixture (a solution) of gases.. Solids and liquids have essentially fixed volumes and are not able to be compressed easily. have volumes that depend on their conditions,

More information

AP Chapter 1, 2, & 3: Atoms, Molecules, and Mass Relationships Name

AP Chapter 1, 2, & 3: Atoms, Molecules, and Mass Relationships Name AP Chapter 1, 2, & 3: Atoms, Molecules, and Mass Relationships Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. AP Chapter 1, 2, & 3: Atoms & Molecules,

More information

INTI COLLEGE MALAYSIA A? LEVEL PROGRAMME CHM 111: CHEMISTRY MOCK EXAMINATION: DECEMBER 2000 SESSION. 37 74 20 40 60 80 m/e

INTI COLLEGE MALAYSIA A? LEVEL PROGRAMME CHM 111: CHEMISTRY MOCK EXAMINATION: DECEMBER 2000 SESSION. 37 74 20 40 60 80 m/e CHM111(M)/Page 1 of 5 INTI COLLEGE MALAYSIA A? LEVEL PROGRAMME CHM 111: CHEMISTRY MOCK EXAMINATION: DECEMBER 2000 SESSION SECTION A Answer ALL EIGHT questions. (52 marks) 1. The following is the mass spectrum

More information

Stoichiometry CHAPTER 12

Stoichiometry CHAPTER 12 CHAPTER 1 Stoichiometry What You ll Learn You will write mole ratios from balanced chemical equations. You will calculate the number of moles and the mass of a reactant or product when given the number

More information

Summer Holidays Questions

Summer Holidays Questions Summer Holidays Questions Chapter 1 1) Barium hydroxide reacts with hydrochloric acid. The initial concentration of the 1 st solution its 0.1M and the volume is 100ml. The initial concentration of the

More information

Solution. Practice Exercise. Concept Exercise

Solution. 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 information

Ch 15: Acids and Bases

Ch 15: Acids and Bases Ch 15: Acids and Bases A c i d s a n d B a s e s C h 1 5 P a g e 1 Homework: Read Chapter 15 Work out sample/practice exercises in the sections, Bonus problems: 39, 41, 49, 63, 67, 83, 91, 95, 99, 107,

More information

(1) e.g. H hydrogen that has lost 1 electron c. anion - negatively charged atoms that gain electrons 16-2. (1) e.g. HCO 3 bicarbonate anion

(1) e.g. H hydrogen that has lost 1 electron c. anion - negatively charged atoms that gain electrons 16-2. (1) e.g. HCO 3 bicarbonate anion GS106 Chemical Bonds and Chemistry of Water c:wou:gs106:sp2002:chem.wpd I. Introduction A. Hierarchy of chemical substances 1. atoms of elements - smallest particles of matter with unique physical and

More information

Moles Lab mole. 1 mole = 6.02 x 1023. This is also known as Avagadro's number Demo amu amu amu

Moles Lab mole. 1 mole = 6.02 x 1023. This is also known as Avagadro's number Demo amu amu amu Moles I. Lab: Rice Counting II. Counting atoms and molecules I. When doing reactions chemists need to count atoms and molecules. The problem of actually counting individual atoms and molecules comes from

More information

A dozen. Molar Mass. Mass of atoms

A dozen. Molar Mass. Mass of atoms A dozen Molar Mass Science 10 is a number of objects. A dozen eggs, a dozen cars, and a dozen people are all 12 objects. But a dozen cars has a much greater mass than a dozen eggs because the mass of each

More information

Name Date Class CHEMICAL QUANTITIES. SECTION 10.1 THE MOLE: A MEASUREMENT OF MATTER (pages 287 296)

Name 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 information

The Mole. Chapter 10. Dimensional Analysis. The Mole. How much mass is in one atom of carbon-12? Molar Mass of Atoms 3/1/2015

The Mole. Chapter 10. Dimensional Analysis. The Mole. How much mass is in one atom of carbon-12? 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 information

Chemical Composition Review Mole Calculations Percent Composition. Copyright Cengage Learning. All rights reserved. 8 1

Chemical Composition Review Mole Calculations Percent Composition. Copyright Cengage Learning. All rights reserved. 8 1 Chemical Composition Review Mole Calculations Percent Composition Copyright Cengage Learning. All rights reserved. 8 1 QUESTION Suppose you work in a hardware store and a customer wants to purchase 500

More information

Ch. 6 Chemical Composition and Stoichiometry

Ch. 6 Chemical Composition and Stoichiometry Ch. 6 Chemical Composition and Stoichiometry The Mole Concept [6.2, 6.3] Conversions between g mol atoms [6.3, 6.4, 6.5] Mass Percent [6.6, 6.7] Empirical and Molecular Formula [6.8, 6.9] Bring your calculators!

More information

Chapter 2 Polar Covalent Bonds: Acids and Bases

Chapter 2 Polar Covalent Bonds: Acids and Bases John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 2 Polar Covalent Bonds: Acids and Bases Modified by Dr. Daniela R. Radu Why This Chapter? Description of basic ways chemists account for chemical

More information

EDEXCEL INTERNATIONAL GCSE CHEMISTRY EDEXCEL CERTIFICATE IN CHEMISTRY ANSWERS SECTION E

EDEXCEL INTERNATIONAL GCSE CHEMISTRY EDEXCEL CERTIFICATE IN CHEMISTRY ANSWERS SECTION E EDEXCEL INTERNATIONAL GCSE CHEMISTRY EDEXCEL CERTIFICATE IN CHEMISTRY ANSWERS SECTION E (To save endless repetition, wherever they are included, comments are intended for homeschooling parents who may

More information

Unit 19 Practice. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question.

Unit 19 Practice. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question. Name: Class: Date: Unit 19 Practice Multiple Choice Identify the choice that best completes the statement or answers the question. 1) The first law of thermodynamics can be given as. A) E = q + w B) =

More information

How much does a single atom weigh? Different elements weigh different amounts related to what makes them unique.

How much does a single atom weigh? Different elements weigh different amounts related to what makes them unique. How much does a single atom weigh? Different elements weigh different amounts related to what makes them unique. What units do we use to define the weight of an atom? amu units of atomic weight. (atomic

More information

Atomic Masses. Chapter 3. Stoichiometry. Chemical Stoichiometry. Mass and Moles of a Substance. Average Atomic Mass

Atomic 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 information

10 Cl atoms. 10 H2O molecules. 8.3 mol HCN = 8.3 mol N atoms 1 mol HCN. 2 mol H atoms 2.63 mol CH2O = 5.26 mol H atoms 1 mol CH O

10 Cl atoms. 10 H2O molecules. 8.3 mol HCN = 8.3 mol N atoms 1 mol HCN. 2 mol H atoms 2.63 mol CH2O = 5.26 mol H atoms 1 mol CH O Chem 100 Mole conversions and stoichiometry worksheet 1. How many Ag atoms are in.4 mol Ag atoms? 6.0 10 Ag atoms 4.4 mol Ag atoms = 1.46 10 Ag atoms 1 mol Ag atoms. How many Br molecules are in 18. mol

More information

Chapter 13 & 14 Practice Exam

Chapter 13 & 14 Practice Exam Name: Class: Date: Chapter 13 & 14 Practice Exam Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Acids generally release H 2 gas when they react with a.

More information

Stoichiometry. Web Resources Chem Team Chem Team Stoichiometry. Section 1: Definitions Define the following terms. Average Atomic mass - Molecule -

Stoichiometry. Web Resources Chem Team Chem Team Stoichiometry. Section 1: Definitions Define the following terms. Average Atomic mass - Molecule - Web Resources Chem Team Chem Team Section 1: Definitions Define the following terms Average Atomic mass - Molecule - Molecular mass - Moles - Avagadro's Number - Conservation of matter - Percent composition

More information

Chapter 13 - LIQUIDS AND SOLIDS

Chapter 13 - LIQUIDS AND SOLIDS Chapter 13 - LIQUIDS AND SOLIDS Problems to try at end of chapter: Answers in Appendix I: 1,3,5,7b,9b,15,17,23,25,29,31,33,45,49,51,53,61 13.1 Properties of Liquids 1. Liquids take the shape of their container,

More information

4.4 Calculations Involving the Mole Concept

4.4 Calculations Involving the Mole Concept 44 Section 43 Questions 1 Define Avogadro s constant, and explain its significance in quantitative analysis 2 Distinguish between the terms atomic mass and molar mass 3 Calculate the mass of a molecule

More information

Part B 2. Allow a total of 15 credits for this part. The student must answer all questions in this part.

Part B 2. Allow a total of 15 credits for this part. The student must answer all questions in this part. Part B 2 Allow a total of 15 credits for this part. The student must answer all questions in this part. 51 [1] Allow 1 credit for 3 Mg(s) N 2 (g) Mg 3 N 2 (s). Allow credit even if the coefficient 1 is

More information

Balancing chemical reaction equations (stoichiometry)

Balancing chemical reaction equations (stoichiometry) Balancing chemical reaction equations (stoichiometry) This worksheet and all related files are licensed under the Creative Commons Attribution License, version 1.0. To view a copy of this license, visit

More information

CHEMICAL FORMULAE AND STOICHIOMETRY

CHEMICAL FORMULAE AND STOICHIOMETRY LOCUS 1 Section - CHEMICAL FORMULAE AND STOICHIOMETRY The language that chemists use to describe the forms of matter and the changes in its composition appears throughout the scientific world. Chemical

More information

Ch. 10 The Mole I. Molar Conversions

Ch. 10 The Mole I. Molar Conversions Ch. 10 The Mole I. Molar Conversions I II III IV A. What is the Mole? A counting number (like a dozen) Avogadro s number (N A ) 1 mole = 6.022 10 23 representative particles B. Mole/Particle Conversions

More information

Solubility of Salts - Ksp. Ksp Solubility

Solubility of Salts - Ksp. Ksp Solubility Solubility of Salts - Ksp We now focus on another aqueous equilibrium system, slightly soluble salts. These salts have a Solubility Product Constant, K sp. (We saw this in 1B with the sodium tetraborate

More information

Stoichiometry of Formulas and Equations

Stoichiometry of Formulas and Equations sil07204_ch03_69-107 8/22/05 15:16 Page 69 CHAPTER THREE Stoichiometry of Formulas and Equations Key Principles The mole (mol) is the standard unit for amount of substance and consists of Avogadro s number

More information

Calculate the molar mass of each of the following: (a) SnO 2. Calculate the molar mass of each of the following: (a) N 2 O 4

Calculate the molar mass of each of the following: (a) SnO 2. Calculate the molar mass of each of the following: (a) N 2 O 4 Calculate the molar mass of each of the following: (a SnO (b BaF (c Al (SO 3 (d MnCl Calculate the molar mass of each of the following: (a N O (b C 8 H 10 (c MgSO. 7 H O (d Ca(C H 3 O (a Mass in grams

More information

Worksheet # 8 Graham/09 Due

Worksheet # 8 Graham/09 Due CHE 100 Worksheet # 8 Graham/09 Name Key Due 1. According to the law of definite proportions, if a sample of a compound contains 7.00 grams of sulfur and 3.50 grams of oxygen, then another sample of the

More information

Type of Chemical Bonds

Type of Chemical Bonds Type of Chemical Bonds Covalent bond Polar Covalent bond Ionic bond Hydrogen bond Metallic bond Van der Waals bonds. Covalent Bonds Covalent bond: bond in which one or more pairs of electrons are shared

More information