Chemistry 4th Edition McMurry/Fay

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Chemistry 4th Edition McMurry/Fay"

Transcription

1 13 Ch a pt e r Chemical Equilibrium Chemistry 4th Edition McMurry/Fay Dr. Paul Charlesworth Michigan Technological University The Equilibrium State 01 Chemical Equilibrium: A state achieved when the rates of the forward and reverse reactions are equal and the concentrations of the reactants and products remain constant. Equilibrium between phases is known as physical equilibrium. Chapter 13 Slide 2 The Equilibrium State 02 Chapter 13 Slide 3 1

2 The Equilibrium State 02 Chemists are interested in these reversible reactions. One example is the following: Chapter 13 Slide 4 The Equilibrium State 03 Chapter 13 Slide 5 The Equilibrium State 03 Graphs of reactant and product concentrations change with time as shown below. Chapter 13 Slide 6 2

3 The Equilibrium State 04 Chapter 13 Slide 7 Equilibrium Constant 01 The equilibrium expression compares reactant and product concentrations. [ Pr oducts K = ]p Reactants [ [ ] r = B] b [ [ A] a = NO 2 ] 2 [ N 2 O 4 ] = From this we obtain a constant (K) for the reaction, which is independent of concentration changes, but dependent on the temperature. Chapter 13 Slide 8 Equilibrium Constant 02 Homogeneous Equilibrium:When all reacting species are in the same phase, all reactants and products are included in the expression. Amounts of components are given as molarity or partial pressure of a gas. [ K c = NO 2 ] 2 [ N 2 O 4 ] K p = P 2 NO 2 P N2O4 Chapter 13 Slide 9 3

4 Equilibrium Constant 03 We can convert between K c and K p using an equation derived from PV = nrt: For aa æ bb K p = K c (0.0821T)?n?n = moles gas products moles of gas reactants?n = b a Chapter 13 Slide 10 Equilibrium Constant 04 The following pictures rerepresent mixtures of A molecules (red) and B molecules (blue), which interconvert according to the equation A æ B. If Mixture (1) is at equilibrium, which of the other mixtures is also at equilibrium? Chapter 13 Slide 11 Equilibrium Constant 05 Write the K p and K c expressions for: 2 N 2 O 5 æ 4 NO 2 + O 2 The equilibrium concentrations for the reaction between CO and Cl 2 to form carbonyl chloride (phosgene gas) CO + Cl 2 æ COCl 2 at 74 C are: [CO] = 1.2 x 10 2 M, [Cl 2 ] = M, and [COCl 2 ] = 0.14 M. Calculate K c and K p. Chapter 13 Slide 12 4

5 Equilibrium Constant 06 Methane (CH 4 ) reacts with hydrogen sulfide to yield H 2 and carbon disulfide, a solvent used in manufacturing. What is the value of K p at 1000 K if the partial pressures in an equilibrium mixture at 1000 K are 0.20 atm of CH 4, 0.25 atm of H 2 S, 0.52 atm of CS 2, and 0.10 atm of H 2? Chapter 13 Slide 13 Equilibrium Constant 07 Heterogeneous Equilibrium:When reacting species are in different phases, solid and liquid phases are excluded from the expression because their concentrations do not change. For CaCO 3 (s) æ CaO(s) + CO 2 K c = [CO 2 ] because CaCO 3 and CaO are solids. Chapter 13 Slide 14 Equilibrium Constant 08 Chapter 13 Slide 15 5

6 Equilibrium Constant 09 Write the equilibrium equation for each of the following reactions: (a) CO 2 + C(s) æ 2 CO (b) Hg(l) + Hg 2+ (aq) æ Hg 2 2+ (aq) (c) 2 Fe(s) + 3 H 2 O æ Fe 2 O 3 (s) + 3 H 2 (d) 2 H 2 O(l) æ 2 H 2 + O 2 Chapter 13 Slide 16 Using Equilibrium Constants 01 We can make the following generalizations concerning the composition of equilibrium mixtures: If K c > 10 3, products predominate over reactants. If K c is very large, the reaction is said to proceed to completion. If K c is in the range 10 3 to 10 3, appreciable concentrations of both reactants and products are present. If K c < 10 3, reactants predominate over products. If K c is very small, the reaction proceeds hardly at all. Chapter 13 Slide 17 Using Equilibrium Constants 02 The reaction quotient (Q c ) is obtained by substituting initial concentrations into the equilibrium constant. Predicts reaction direction. Q c > K c Q c = K c Q c < K c System proceeds to form reactants. System is at equilibrium. System proceeds to form products. Chapter 13 Slide 18 6

7 Using Equilibrium Constants 03 Predicting the direction of a reaction. Chapter 13 Slide 19 Using Equilibrium Constants 04 The equilibrium constant (K c ) for the formation of nitrosyl chloride, from nitric oxide and chlorine gas: 2 NO + Cl 2 æ 2 NOCl is 6.5 x 10 4 at 35 C. In an experiment, 2.0 x 10 2 moles of NO, 8.3 x 10 3 moles of Cl 2, and 6.8 moles of NOCl are mixed in a 2.0-L flask. In which direction will the system proceed to reach equilibrium? Chapter 13 Slide 20 Using Equilibrium Constants 05 Knowing K allows us to calculate equilibrium concentrations from initial concentrations. We use the Initial Change Equilibrium method. cis-stilbene æ trans-stilbene Initial (M) Change (M) x +x Equil ibrium (M) (0.850 x) x Use K c =24 to determine equilibrium concentrations. Chapter 13 Slide 21 7

8 Using Equilibrium Constants 06 A mixture of mol H 2 and mol I 2 was placed in a 1.00-L stainless steel flask at 700 C. The equilibrium constant K c for the reaction H 2 + I 2 æ 2 HI is 57 at this temperature. Calculate the equilibrium concentrations. If the starting concentration of HI was M, calculate the new equilibrium concentrations. If the initial concentrations are [H 2 ] = M and [I 2 ] = M, calculate the equilibrium concentrations. Chapter 13 Slide 22 Le Châtelier s Principle 01 Le Châtelier s principle: If an external stress is applied to a system at equilibrium, the system adjusts in such a way that the stress is partially offset. Chapter 13 Slide 23 Le Châtelier s Principle 02 Concentration Changes: The concentration stress of an added reactant or product is relieved by reaction in the direction that consumes the added substance. The concentration stress of a removed reactant or product is relieved by reaction in the direction that replenishes the removed substance. Chapter 13 Slide 24 8

9 Le Châtelier s Principle 03 Haber process for synthesis of ammonia. N H 2 æ 2 NH 3 K c = at 700 K Given an equilibrium mixture of 0.50 M N 2, 3.00 M H 2, and 1.98 M NH 3 at 700 K, what happens when the concentration of N 2 is increased to 1.50 M? Le Châtelier s principle tells us the reaction will relieve the stress by converting the N 2 to NH 3. Chapter 13 Slide 25 Le Châtelier s Principle 04 Chapter 13 Slide 26 Le Châtelier s Principle 05 Chapter 13 Slide 27 9

10 Le Châtelier s Principle 06 The reaction of iron(iii) oxide with carbon monoxide occurs in a blast furnace when iron ore is reduced to iron metal: Fe 2 O 3 (s) + 3 CO æ 2 Fe(l) + 3 CO 2 Use Le Châtelier s principle to predict the direction of reaction when an equilibrium mixture is disturbed by: (a) Adding Fe 2 O 3 (b) Removing CO 2 (c) Removing CO Chapter 13 Slide 28 Le Châtelier s Principle 07 Volume and Pressure Changes: Only reactions containing gases are affected by changes in volume and pressure. Increasing pressure = Decreasing volume PV = nrt tells us that increasing pressure or decreasing volume increases concentration. Chapter 13 Slide 29 Le Châtelier s Principle 08 N H 2 æ 2 NH 3 K c = at 700 K Chapter 13 Slide 30 10

11 Le Châtelier s Principle 09 Consider the reaction: N 2 O 4 æ 2 NO 2, taking place in a cylinder with a volume = 1 unit. [NO 2 ] = 2 mol/1 = 2 [N 2 O 4 ] = 1 mol/1 = 1 K = [NO 2 ]2 [N 2 O 4 ] = 4 Chapter 13 Slide 31 Le Châtelier s Principle 10 The Volume is then halved, which is equivalent to doubling the pressure. [NO 2 ] = 2 mol/0.5 = 4 [N2O4] = 1 mol/0.5 = 2 Q = [NO 2 ] 2 = 8 [N 2 O 4 ] Since Q > K, the [product] is too high and the reaction progresses in the reverse direction. Chapter 13 Slide 32 Le Châtelier s Principle 11 Does the number of moles of reaction products increase, decrease, or remain the same when each of the following equilibria is subjected to a decrease in pressure by increasing the volume. 1. PCl 5 æ PCl 3 + Cl 2 2. CaO(s) + CO 2 æ CaCO 3 (s) 3. 3 Fe(s) + 4 H 2 O æ Fe 3 O 4 (s) + 4 H 2 Chapter 13 Slide 33 11

12 Le Châtelier s Principle 12 The following picture represents the equilibrium mixture for the gas-phase reaction A 2 æ 2A. Draw a picture that shows how the concentrations change when the pressure is increased by decreasing the volume. Chapter 13 Slide 34 Le Châtelier s Principle 13 Temperature Changes: Changes in temperature can change the equilibrium constant. Endothermic processes are favored when temperature increases. Exothermic processes are favored when temperature decreases. Chapter 13 Slide 35 Le Châtelier s Principle 14 Consider the reaction N H 2 æ 2 NH 3 which is exothermic by 92.2 kj. Chapter 13 Slide 36 12

13 Le Châtelier s Principle 15 In the first step of the Ostwald process for synthesis of nitric acid, ammonia is oxidized to nitric oxide by the reaction: 4 NH O 2 æ 4 NO + 6 H 2 O?H = kj How does the equilibrium amount vary with an increase in temperature? Chapter 13 Slide 37 Le Châtelier s Principle 16 The following pictures represent the composition of the equilibrium mixture at 400 K and 500 K for the reaction A + B æ AB. Is the reaction endothermic or exothermic? Chapter 13 Slide 38 Le Châtelier s Principle 17 Catalysis: No effect. Chapter 13 Slide 39 13

Chemical Equilibrium

Chemical Equilibrium Chapter 13 Chemical Equilibrium Equilibrium Physical Equilibrium refers to the equilibrium between two or more states of matter (solid, liquid and gas) A great example of physical equilibrium is shown

More information

Chapter 13. Chemical Equilibrium

Chapter 13. Chemical Equilibrium Chapter 13 Chemical Equilibrium Chapter 13 Preview Chemical Equilibrium The Equilibrium condition and constant Chemical equilibrium, reactions, constant expression Equilibrium involving Pressure Chemical

More information

Chemical Equilibrium

Chemical Equilibrium Chemical Equilibrium Chapter 14 1 Equilibrium is a state in which there are no observable changes as time goes by. Chemical equilibrium is achieved when: the rates of the forward and reverse reactions

More information

K c = [C]c [D] d [A] a [B] b. k f [NO 2 ] = k r [N 2 O 4 ] = K eq = The Concept of Equilibrium. Chapter 15 Chemical Equilibrium

K c = [C]c [D] d [A] a [B] b. k f [NO 2 ] = k r [N 2 O 4 ] = K eq = The Concept of Equilibrium. Chapter 15 Chemical Equilibrium Chapter 15 Chemical Equilibrium Learning goals and key skills: Understand what is meant by chemical equilibrium and how it relates to reaction rates Write the equilibrium-constant expression for any reaction

More information

CHEMICAL EQUILIBRIUM

CHEMICAL EQUILIBRIUM Chemistry 10 Chapter 14 CHEMICAL EQUILIBRIUM Reactions that can go in both directions are called reversible reactions. These reactions seem to stop before they go to completion. When the rate of the forward

More information

Chapter 15: Chemical Equilibrium: How Much Product Does a Reaction Really Make?

Chapter 15: Chemical Equilibrium: How Much Product Does a Reaction Really Make? Chapter 15: Chemical Equilibrium: How Much Product Does a Reaction Really Make? End-of-Chapter Problems: 15.1-15.10, 15.13-15.14, 15.17-15.99, 15.102-15.104 Example: Ice melting is a dynamic process: H

More information

Chapter 14 Chemical Equilibrium

Chapter 14 Chemical Equilibrium Chapter 14 Chemical Equilibrium Forward reaction H 2 (g) + I 2 (g) 2HI(g) Reverse reaction 2HI(g) H 2 (g) + I 2 (g) At equilibrium H 2 (g) + I 2 (g) 2HI(g) Chemical equilibrium is reached when reactants

More information

Chapter 14. CHEMICAL EQUILIBRIUM

Chapter 14. CHEMICAL EQUILIBRIUM Chapter 14. CHEMICAL EQUILIBRIUM 14.1 THE CONCEPT OF EQUILIBRIUM AND THE EQUILIBRIUM CONSTANT Many chemical reactions do not go to completion but instead attain a state of chemical equilibrium. Chemical

More information

CHAPTER 14 (MOORE) CHEMICAL EQUILIBRIUM

CHAPTER 14 (MOORE) CHEMICAL EQUILIBRIUM CHAPTER 14 (MOORE) CHEMICAL EQUILIBRIUM This chapter deals with chemical equilibrium, or how far chemical reactions proceed. Some reactions convert reactants to products with near 100% efficiency but others

More information

Chemical Equilibrium. Rate Forward Reaction = Rate Reverse Reaction. Chapter 14. Hill, Petrucci, McCreary & Perry 4 th. Ed.

Chemical Equilibrium. Rate Forward Reaction = Rate Reverse Reaction. Chapter 14. Hill, Petrucci, McCreary & Perry 4 th. Ed. Chapter 14 Chemical Equilibrium Hill, Petrucci, McCreary & Perry 4 th Ed. Chemical Equilibrium Many Reactions seem to STOP before all the reactants are used up. The Concentrations of Reactants and Products

More information

Equilibrium Notes Ch 14:

Equilibrium Notes Ch 14: Equilibrium Notes Ch 14: Homework: E q u i l i b r i u m P a g e 1 Read Chapter 14 Work out sample/practice exercises in the sections, Bonus Chapter 14: 23, 27, 29, 31, 39, 41, 45, 51, 57, 63, 77, 83,

More information

Principles of Reactivity: Chemical Equilibria

Principles of Reactivity: Chemical Equilibria Principles of Reactivity: Chemical Equilibria This chapter addresses the principle of equilibrium equilibrium What can you do to reestablish equilibrium? non-equilibrium Whose principle supports this?

More information

Sample Exercise 15.1 Writing Equilibrium-Constant Expressions

Sample Exercise 15.1 Writing Equilibrium-Constant Expressions Sample Exercise 15.1 Writing Equilibrium-Constant Expressions Write the equilibrium expression for K c for the following reactions: Solution Analyze: We are given three equations and are asked to write

More information

Gas Phase Equilibrium

Gas Phase Equilibrium Gas Phase Equilibrium Chemical Equilibrium Equilibrium Constant K eq Equilibrium constant expression Relationship between K p and K c Heterogeneous Equilibria Meaning of K eq Calculations of K c Solving

More information

Answers: Given: No. [COCl 2 ] = K c [CO][Cl 2 ], but there are many possible values for [CO]=[Cl 2 ]

Answers: Given: No. [COCl 2 ] = K c [CO][Cl 2 ], but there are many possible values for [CO]=[Cl 2 ] Chemical Equilibrium What are the concentrations of reactants and products at equilibrium? How do changes in pressure, volume, temperature, concentration and the use of catalysts affect the equilibrium

More information

AP* Chemistry CHEMICAL EQUILIBRIA: GENERAL CONCEPTS

AP* Chemistry CHEMICAL EQUILIBRIA: GENERAL CONCEPTS AP* Chemistry CHEMICAL EQUILIBRIA: GENERAL CONCEPTS THE NATURE OF THE EQUILIBRIUM STATE: Equilibrium is the state where the rate of the forward reaction is equal to the rate of the reverse reaction. At

More information

CHEM 1332 CHAPTER 14

CHEM 1332 CHAPTER 14 CHEM 1332 CHAPTER 14 1. Which is a proper description of chemical equilibrium? The frequencies of reactant and of product collisions are identical. The concentrations of products and reactants are identical.

More information

Equilibrium Practice Problems

Equilibrium Practice Problems Equilibrium Practice Problems 1. Write the equilibrium expression for each of the following reactions: N 2 (g) + 3 H 2 (g) 2 NH 3 (g) K = [NH 3 ] 2 [N 2 ] [H 2 ] 3 I 2 (s) + Cl 2 (g) 2 ICl (g) K = [ICl]

More information

EQUILIBRIUM. Consider the reversible system initially consisting of reactants only.

EQUILIBRIUM. Consider the reversible system initially consisting of reactants only. EQUILIBRIUM When non reversible chemical reactions proceed to completion, the concentration of the reactants gradually decrease, until there is NO limiting reactant remaining. Most chemical reactions,

More information

Equilibrium. Equilibrium 1. Examples of Different Equilibria. K p H 2 + N 2 NH 3 K a HC 2 H 3 O 2 H C 2 H 3 O 2 K sp SrCrO 4 Sr CrO 4

Equilibrium. Equilibrium 1. Examples of Different Equilibria. K p H 2 + N 2 NH 3 K a HC 2 H 3 O 2 H C 2 H 3 O 2 K sp SrCrO 4 Sr CrO 4 Equilibrium 1 Equilibrium Examples of Different Equilibria K p H 2 + N 2 NH 3 K a HC 2 H 3 O 2 H + - + C 2 H 3 O 2 K sp SrCrO 4 Sr 2+ 2- + CrO 4 Equilibrium deals with: What is the balance between products

More information

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. A.P. Chemistry Practice Test - Ch. 13: Equilibrium Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) At equilibrium,. A) the rates of the forward

More information

Chapter 13. Chemical Equilibrium

Chapter 13. Chemical Equilibrium Chapter 13 Chemical Equilibrium Section 13.1 The Equilibrium Condition Section 13.1 The Equilibrium Condition Section 13.1 The Equilibrium Condition Section 13.1 The Equilibrium Condition Section 13.1

More information

Name AP Chemistry / / Chapter 13 Collected AP Exam Free Response Questions 1980 2010 Answers

Name AP Chemistry / / Chapter 13 Collected AP Exam Free Response Questions 1980 2010 Answers Name AP Chemistry / / Chapter 13 Collected AP Exam Free Response Questions 1980 2010 Answers 1980 - #6 NH 4 Cl(s) NH 3 (g) + HCl(g) ΔH = +42.1 kilocalories Suppose the substances in the reaction above

More information

Chapter 20. Thermodynamics p. 811 842. Spontaneity. What have we learned about spontaneity during this course?

Chapter 20. Thermodynamics p. 811 842. Spontaneity. What have we learned about spontaneity during this course? Chapter 20 p. 811 842 Spontaneous process: Ex. Nonspontaneous process: Ex. Spontaneity What have we learned about spontaneity during this course? 1) Q vs. K? 2) So.. Spontaneous process occurs when a system

More information

We will be looking at: A. Judging the extent of a reaction B. Predicting the direction of a reaction C. Calculating equilibrium concentrations

We will be looking at: A. Judging the extent of a reaction B. Predicting the direction of a reaction C. Calculating equilibrium concentrations 13.5 Using the Equilibrium Constant We will be looking at: A. Judging the extent of a reaction B. Predicting the direction of a reaction C. Calculating equilibrium concentrations A. Judging the extent

More information

A k 1. At equilibrium there is no net change in [A] or [B], namely d[a] dt

A k 1. At equilibrium there is no net change in [A] or [B], namely d[a] dt Chapter 15: Chemical Equilibrium Key topics: Equilibrium Constant Calculating Equilibrium Concentrations The Concept of Equilibrium Consider the reaction A k 1 k 1 B At equilibrium there is no net change

More information

Chemical Equilibrium - Chapter 14

Chemical Equilibrium - Chapter 14 Chemical Equilibrium - Chapter 14 1. Dynamic Equilibrium a A + b B c C + d D At Equilibrium: Reaction is proceeding in both directions at the same rate. There is no net change in concentrations of reactants

More information

Moles and Chemical Reactions. Moles and Chemical Reactions. Molar mass = 2 x 12.011 + 6 x 1.008 + 1 x15.999 = 46.069 g/mol

Moles 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 information

Worked solutions to student book questions Chapter 16 Controlling the yield of reactions

Worked solutions to student book questions Chapter 16 Controlling the yield of reactions E1. Write an equation to show the equilibrium that exists between NaI(s) and Na + (aq) and I (aq). AE1. NaI(s) Na + (aq) + I (aq) E. a Sketch a graph of the change in the radioactivity of the solution

More information

Consider: N 2 (g) + 3H 2 (g) 2NH 3 (g) G = -32.90 kj/mol. conc. time

Consider: N 2 (g) + 3H 2 (g) 2NH 3 (g) G = -32.90 kj/mol. conc. time 5.111 Lecture Summary #19 CHEMICAL EQUILIBRIUM (Chapter 9 Section 9.0-9.9) Topics Nature of Chemical Equilibrium Meaning of K Relationship between Equilibrium Expressions External Effects on K 19.1 Chemical

More information

Chemistry B11 Chapter 4 Chemical reactions

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

More information

IB Chemistry. DP Chemistry Review

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

More information

Enthalpy, Entropy, and Free Energy Calculations

Enthalpy, Entropy, and Free Energy Calculations Adapted from PLTL The energies of our system will decay, the glory of the sun will be dimmed, and the earth, tideless and inert, will no longer tolerate the race which has for a moment disturbed its solitude.

More information

Ch14 Chemical Equilibrium. Modified by Dr. Cheng-Yu Lai

Ch14 Chemical Equilibrium. Modified by Dr. Cheng-Yu Lai Ch14 Chemical Equilibrium Modified by Dr. Cheng-Yu Lai CHEMICAL EQUILIBRIUM Chemical Equilibrium: Chemical Equilibrium When the rate of the forward reaction equals the rate of the reverse reaction and

More information

Chapter 13 - Chemical Equilibrium

Chapter 13 - Chemical Equilibrium Chapter 1 - Chemical Equilibrium Intro A. Chemical Equilibrium 1. The state where the concentrations of all reactants and products remain constant with time. All reactions carried out in a closed vessel

More information

Chemical Equilibrium-A Dynamic Equilibrium

Chemical Equilibrium-A Dynamic Equilibrium Chemical Equilibrium-A Dynamic Equilibrium Page 1 When compounds react, they eventually form a mixture of products and (unreacted) reactants, in a dynamic equilibrium Much like water in a U-shape tube,

More information

Chapter 15 Chemical Equilibrium

Chapter 15 Chemical Equilibrium Chapter 15 Chemical Equilibrium Chemical reactions can reach a state of dynamic equilibrium. Similar to the equilibrium states reached in evaporation of a liquid in a closed container or the dissolution

More information

CHM1 Review for Exam 9

CHM1 Review for Exam 9 Topics 1. Reaction Types a. Combustion b. Synthesis c. Decomposition d. Single replacement i. Metal activity series ii. Nonmetal activity series e. Double replacement i. Precipitates and solubility rules

More information

Test Review # 9. Chemistry R: Form TR9.13A

Test Review # 9. Chemistry R: Form TR9.13A Chemistry R: Form TR9.13A TEST 9 REVIEW Name Date Period Test Review # 9 Collision theory. In order for a reaction to occur, particles of the reactant must collide. Not all collisions cause reactions.

More information

CH 223 Chapter Thirteen Concept Guide

CH 223 Chapter Thirteen Concept Guide CH 223 Chapter Thirteen Concept Guide 1. Writing Equilibrium Constant Expressions Write the equilibrium constant (K c ) expressions for each of the following reactions: (a) Cu(OH) 2 (s) (b) Cu(NH 3 ) 4

More information

Chemistry 212 EXAM 1 January 27, 2004

Chemistry 212 EXAM 1 January 27, 2004 1 Chemistry 212 EXAM 1 January 27, 2004 _100 (of 100) KEY Name Part 1: Multiple Choice. (1 point each, circle only one answer, 1. Consider the following rate law: Rate = k[a] n [B] m How are the exponents

More information

Potassium + Chlorine. K(s) + Cl 2 (g) 2 KCl(s)

Potassium + Chlorine. K(s) + Cl 2 (g) 2 KCl(s) Types of Reactions Consider for a moment the number of possible chemical reactions. Because there are millions of chemical compounds, it is logical to expect that there are millions of possible chemical

More information

Chemical Equations & Stoichiometry

Chemical 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 information

SECTION 14 CHEMICAL EQUILIBRIUM

SECTION 14 CHEMICAL EQUILIBRIUM 1-1 SECTION 1 CHEMICAL EQUILIBRIUM Many chemical reactions do not go to completion. That is to say when the reactants are mixed and the chemical reaction proceeds it only goes to a certain extent, and

More information

2. Write a balanced chemical equation which corresponds to the following equilibrium constant expression. 1/2 3/ 2

2. Write a balanced chemical equation which corresponds to the following equilibrium constant expression. 1/2 3/ 2 Practice Problems for Chem. 1B Exam 1 F2011 These represent the concepts covered for exam 1. There may be some additional net ionic equations from chem. 1A. This is not the exact exam! Sections 16.1-16.3

More information

Chapter 14. Review Skills

Chapter 14. Review Skills Chapter 14 The Process of Chemical Reactions ave you ever considered becoming a chemical engineer? The men and women in this profession develop industrial processes for the large-scale production of the

More information

CHAPTER 14 CHEMICAL EQUILIBRIUM

CHAPTER 14 CHEMICAL EQUILIBRIUM CHATER 14 CHEMICAL EQUILIBRIUM roblem Categories Biological: 14.98. Conceptual: 14.1, 14., 14.9, 14.5, 14.54, 14.55, 14.56, 14.57, 14.58, 14.59, 14.60, 14.61, 14.6, 14.66, 14.67, 14.68, 14.69, 14.81, 14.91,

More information

CHEM1612 2014-N-2 November 2014

CHEM1612 2014-N-2 November 2014 CHEM1612 2014-N-2 November 2014 Explain the following terms or concepts. Le Châtelier s principle 1 Used to predict the effect of a change in the conditions on a reaction at equilibrium, this principle

More information

Chemical Equilibrium. Chemical Equilibrium

Chemical Equilibrium. Chemical Equilibrium Chemical Equilibrium When some types of chemical reactions occur in the gas or solution phases, these reaction attain chemical equilibrium, i.e., the reaction does not go to completion, but the reaction

More information

Chapter 13 Chemical Equilibrium. Equilibrium is Dynamic. The Equilibrium Constant. Equilibrium and Catalysts. Characteristics of Chemical Equilibrium

Chapter 13 Chemical Equilibrium. Equilibrium is Dynamic. The Equilibrium Constant. Equilibrium and Catalysts. Characteristics of Chemical Equilibrium Characteristics of Chemical Equilibrium John W. Moore Conrad L. Stanitski Peter C. Jurs http://academic.cengage.com/chemistry/moore Chapter 13 Chemical Equilibrium Many reactions fail to go to completion.

More information

Stoichiometry Chapter 9 Assignment & Problem Set

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

More information

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

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

More information

CHEM 102 CLASS NOTES Prof. Upali Siriwardane, Chemistry Program, Louisiana Tech University, Ruston, LA 71272 CHAPTER 14, Chemical Equilibrium Chapter

CHEM 102 CLASS NOTES Prof. Upali Siriwardane, Chemistry Program, Louisiana Tech University, Ruston, LA 71272 CHAPTER 14, Chemical Equilibrium Chapter CHEM 10 CLASS NOTES Prof. Upali Siriwardane, Chemistry Program, Louisiana Tech University, Ruston, LA 717 CHAPTER 14, Chemical Equilibrium Chapter 14. Chemical Equilibrium 14.1 Characteristics of Chemical

More information

System. System, Boundary and surroundings: Nature of heat and work: Sign convention of heat: Unit-7 Thermodynamics

System. System, Boundary and surroundings: Nature of heat and work: Sign convention of heat: Unit-7 Thermodynamics Unit-7 Thermodynamics Introduction: The term Thermo means heat and dynamics means flow or movement.. So thermodynamics is concerned with the flow of heat. The different forms of the energy are interconvertible

More information

Chemical Equilibria & the Application of Le Châtelier s Principle to General Equilibria. Example of Equilibrium. !A(g) + "B(g)!

Chemical Equilibria & the Application of Le Châtelier s Principle to General Equilibria. Example of Equilibrium. !A(g) + B(g)! Chemical Equilibria & the Application of Le Châtelier s Principle to General Equilibria CHEM 102H T. Hughbanks Example of Equilibrium N 2 + 3H 2! 2 NH 3 Reactions can occur, in principle, in either direction.

More information

STOICHIOMETRY ANALOGY

STOICHIOMETRY ANALOGY STOICHIOMETRY ANALOGY Stoichiometry is the quantitative relationship between the reactants and products in a balanced chemical equation. Stoichiometry allows chemists to predict how much of a reactant

More information

Name AP CHEM / / Collected AP Exam Essay Answers for Chapter 16

Name AP CHEM / / Collected AP Exam Essay Answers for Chapter 16 Name AP CHEM / / Collected AP Exam Essay Answers for Chapter 16 1980 - #7 (a) State the physical significance of entropy. Entropy (S) is a measure of randomness or disorder in a system. (b) From each of

More information

Chemical Equilibrium. Chapter 13

Chemical Equilibrium. Chapter 13 Chemical Equilibrium Chapter 13 Chemical Equilibrium When neither the products nor the reactant concentrations change any more with time. Chemical Equilibrium When the forward rate of reaction is equal

More information

Guide to Chapter 13. Chemical Equilibrium

Guide to Chapter 13. Chemical Equilibrium Guide to Chapter 13. Chemical Equilibrium We will spend five lecture days on this chapter. During the first class meeting we will focus on how kinetics makes a segue into equilibrium. We will learn how

More information

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

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

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

EQUILIBRIUM. Academic Success Center

EQUILIBRIUM. Academic Success Center EQUILIBRIUM Academic Success Center Definition Equilibrium is a state where the concentrations of the reactants and products no longer change with time. This doesn t mean there is no movement between the

More information

Test 2 Equilibrium and Chemical Energy

Test 2 Equilibrium and Chemical Energy Multiple Choice (0 marks - for each question). In a reversible reaction, equilibrium is reached when A molecules of the reactant cease to change into molecules of the product B the concentrations of reactants

More information

Chemical Equilibrium. Chapter 17: Keeping the chemical themes straight. Chapter 17 Homework Problems. N2O4 (g) 2NO2 (g)

Chemical Equilibrium. Chapter 17: Keeping the chemical themes straight. Chapter 17 Homework Problems. N2O4 (g) 2NO2 (g) Chapter 17: Chemical Equilibrium Equilibrium: The Extent of Chemical Reactions 17.1 The Dynamic Nature of the Equilibrium State 17. The Reaction Quotient and the Equilibrium Constant 17.3 Expressing Equilibria

More information

Molecular Formula: Example

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

More information

Identify the letter of the choice that best completes the statement or answers the question.

Identify the letter of the choice that best completes the statement or answers the question. Chemistry Test - Chapter 10 Chemical Equations Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. When balancing a chemical equation, insert

More information

21 st Century Chemistry Multiple Choice Question in Topic 3 Metals Unit 11

21 st Century Chemistry Multiple Choice Question in Topic 3 Metals Unit 11 21 st Century Chemistry Multiple Choice Question in Topic 3 Metals Unit 11 1. Consider the equation: 2Ca(s) + O 2 (g) 2CaO(s) Which of the following statements are correct? (1) Calcium and oxygen are reactants.

More information

Equilibrium Lecture #1. Schweitzer

Equilibrium Lecture #1. Schweitzer Equilibrium Lecture #1 Schweitzer What is equilibrium? Remember Equilibrium process between to competing reactions. At equilibrium the forward process is equal to the reverse process. *** It appears that

More information

Chemistry Final Exam Review

Chemistry Final Exam Review Name: Date: Block: Chemistry Final Exam Review 2012-2013 Unit 1: Measurement, Numbers, Scientific Notation, Conversions, Dimensional Analysis 1. Write 0.000008732 in scientific notation 8.732x10-6 2. Write

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

AP Chemistry 2009 Scoring Guidelines

AP Chemistry 2009 Scoring Guidelines AP Chemistry 2009 Scoring Guidelines The College Board The College Board is a not-for-profit membership association whose mission is to connect students to college success and opportunity. Founded in 1900,

More information

Mr. Bracken. Multiple Choice Review: Thermochemistry

Mr. Bracken. Multiple Choice Review: Thermochemistry Mr. Bracken AP Chemistry Name Period Multiple Choice Review: Thermochemistry 1. If this has a negative value for a process, then the process occurs spontaneously. 2. This is a measure of how the disorder

More information

Equilibrium. Ron Robertson

Equilibrium. Ron Robertson Equilibrium Ron Robertson Basic Ideas A. Extent of Reaction Many reactions do not go to completion. Those that do not are reversible with a forward reaction and reverse reaction. To be really correct we

More information

IN CHAPTER 13, we examined how fast a chemical reaction occurs. In this chapter we. Chemical Equilibrium

IN CHAPTER 13, we examined how fast a chemical reaction occurs. In this chapter we. Chemical Equilibrium 14 Chemical Equilibrium Every system in chemical equilibrium, under the influence of a change of any one of the factors of equilibrium, undergoes a transformation... [that produces a change]... in the

More information

Chemical Equilibrium. Part A Unit-based exercise. Topic 11. Unit 39 An introduction to chemical equilibrium. Fill in the blanks.

Chemical Equilibrium. Part A Unit-based exercise. Topic 11. Unit 39 An introduction to chemical equilibrium. Fill in the blanks. Topic 11 hemical Equilibrium Part A Unit-based exercise Unit 39 An introduction to chemical equilibrium Fill in the blanks 1 hemical reaction that take place in one direction only are known as irreversible

More information

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

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

More information

CHEMISTRY Practice exam #4 answer key October 16, 2007

CHEMISTRY Practice exam #4 answer key October 16, 2007 CHEMISTRY 123-01 Practice exam #4 answer key October 16, 2007 1. An endothermic reaction causes the surroundings to a. warm up. b. become acidic. c. condense. 2. Which of the following is an example of

More information

CHAPTER 17 EQUILIBRIUM: THE EXTENT OF CHEMICAL REACTIONS

CHAPTER 17 EQUILIBRIUM: THE EXTENT OF CHEMICAL REACTIONS CHATER 17 EQUILIBRIUM: THE EXTENT OF CHEMICAL REACTIONS 17.1 If the rate of the forward reaction exceeds the rate of reverse reaction, products are formed faster than they are consumed. The change in reaction

More information

Chemical Reactions: Energy, Rates and Equilibrium

Chemical Reactions: Energy, Rates and Equilibrium Chemical Reactions: Energy, Rates and Equilibrium Chapter 7 Heat Changes During Chemical Reactions Bond Dissociation Energy- The amount of energy that must be supplied to break a bond and separate the

More information

Chemistry: Chemical Equations

Chemistry: Chemical Equations Chemistry: Chemical Equations Write a balanced chemical equation for each word equation. Include the phase of each substance in the equation. Classify the reaction as synthesis, decomposition, single replacement,

More information

b. Calculate the value of the equilibrium constant at 127ºC for the reaction 2NH 3 (g) N 2 (g) + 3H 2 (g)

b. Calculate the value of the equilibrium constant at 127ºC for the reaction 2NH 3 (g) N 2 (g) + 3H 2 (g) 1. Write the equilibrium expression for the following reaction: 4NH 3 (g) + 7O 2 (g) 4NO 2 (g) + 6H 2 O(g) 2. The following equilibrium concentrations were observed for this reaction at 127ºC: N 2 (g)

More information

Three Stooges in Chemical Reactions

Three Stooges in Chemical Reactions Three Stooges in Chemical Reactions Introduction: Amina Khalifa El-Ashmawy, Ph.D. Gezahegn Chaka, Ph.D. Collin College Department of Chemistry Imagine an old black and white television comedy like the

More information

Stoichiometry (greek): Stoicheion element, metry to measure

Stoichiometry (greek): Stoicheion element, metry to measure Stoichiometry Stoichiometry (greek): Stoicheion element, metry to measure Balanced Chemical equation: Skills Tells Ex. formula writing balancing equations substances involved in the chemical rxn relationship

More information

Problem Solving. Stoichiometry of Gases

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.

More information

SUPPLEMENTARY TOPIC 3 ENERGY AND CHEMICAL REACTIONS

SUPPLEMENTARY TOPIC 3 ENERGY AND CHEMICAL REACTIONS SUPPLEMENTARY TOPIC 3 ENERGY AND CHEMICAL REACTIONS Rearranging atoms. In a chemical reaction, bonds between atoms in one or more molecules (reactants) break and new bonds are formed with other atoms to

More information

CaCO 3 (s) CaO(s) + CO 2 (g)

CaCO 3 (s) CaO(s) + CO 2 (g) CaCO 3 (s) CaO(s) + CO 2 (g) When heated, calcium carbonate decomposes according to the equation above. In a study of the decomposition of calcium carbonate, a student added a 50.0 g sample of powdered

More information

CHAPTER 12 GASES AND THEIR BEHAVIOR

CHAPTER 12 GASES AND THEIR BEHAVIOR Chapter 12 Gases and Their Behavior Page 1 CHAPTER 12 GASES AND THEIR BEHAVIOR 12-1. 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 12-2. Nitrogen

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

12.1 How do sub-atomic particles help us to understand the structure of substances?

12.1 How do sub-atomic particles help us to understand the structure of substances? 12.1 How do sub-atomic particles help us to understand the structure of substances? Simple particle theory is developed in this unit to include atomic structure and bonding. The arrangement of electrons

More information

CHEMICAL KINETICS (RATES OF REACTION)

CHEMICAL KINETICS (RATES OF REACTION) 1 CHEMICAL KINETICS (RATES OF REACTION) Introduction Chemical kinetics is concerned with the dynamics of chemical reactions such as the way reactions take place and the rate (speed) of the process. Collision

More information

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

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

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

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 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) +

More information

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

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.

More information

AP Chemistry 2004 Scoring Guidelines Form B

AP Chemistry 2004 Scoring Guidelines Form B AP Chemistry 2004 Scoring Guidelines Form B The materials included in these files are intended for noncommercial use by AP teachers for course and exam preparation; permission for any other use must be

More information

Limiting Reactants and Percentage Yield

Limiting Reactants and Percentage Yield Section 3 Main Ideas One reactant limits the product of a reaction. Comparing the actual and theoretical yields helps chemists determine the reaction s efficiency. Limiting Reactants and Percentage Yield

More information

CHEMICAL REACTIONS. Chemistry 51 Chapter 6

CHEMICAL REACTIONS. Chemistry 51 Chapter 6 CHEMICAL REACTIONS A chemical reaction is a rearrangement of atoms in which some of the original bonds are broken and new bonds are formed to give different chemical structures. In a chemical reaction,

More information

Unit 10A Stoichiometry Notes

Unit 10A Stoichiometry Notes Unit 10A Stoichiometry Notes Stoichiometry 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 information

Mass and Moles of a Substance

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

More information

Chemical Reactions, Counting Atoms, and Balancing Chemical Equations.

Chemical Reactions, Counting Atoms, and Balancing Chemical Equations. Chemical Reactions, Counting Atoms, and Balancing Chemical Equations. A Chemical Reaction is A process where one or more elements or compounds are changed into one or more different substances A process

More information