Chem II:Gibbs Free Energy and Chemical Equilibrium Infinite Campus Update: Thermochemistry Exam(24pts.) Gibbs Free Energy Textbook Problems (10pts.) Spontaneous Reaction Quiz (10pts.) Objectives: Review Gibbs Free Energy Equation Review factors that influence speed of reactions. Determine what chemical equilibrium is for reversible reactions. Identify stresses that alter the chemical equilibrium position of a system. Explain what the value of Keq indicates about the position of equilibrium.

Gibbs Free Energy Equation Complete Qts. 497 from textbook problems Explain whether or not this reaction increases or decreases in entropy. Explain whether or not this reaction increases or decrease in enthalpy Explain whether or not this reaction is spontaneous or not.

Gibbs Free Energy Review

Chemical Reactions Rates Reaction Rates = how fast the reactants chemically change into the products. Collision Theory: Reactant particles will form products when reactants collide: at the right position. and exchange the right amount of kinetic energy.

Chemical Reaction Energy Diagram Activation Energy: The amount of energy needed to chemically convert reactants to products.

Rates of Chemical Reactions What are factors that can affect speed of reactions?

Chem II: 4.14.15 Due: Gibbs Free Energy Textbook Problem s Objectives: Review factors that influence speed of reactions. Determine what chemical equilibrium is for reversible reactions. Identify stresses that alter the chemical equilibrium position of a system.

Chemical Reaction Rate 1. Use the graph below to define what a chemical reaction rate is. http://www.fccj.us/chm2046/SampleTest/46M10iAnswers.htm http://www.fccj.us/chm2046/SampleTest/46M10iAnswers.htm

Rates of Chemical Reactions 2.Explain what you would do with each factor below to increase the rate of a chemical reaction? Temperature Concentration of Reactants Surface Area of Reactants Catalysts Inhibitors

Catalysts Catalysts speed up reactions, but they are not apart of the chemical reaction. Ex. Enzymes keep your body temperature around 37oC (98 oF) by speeding up important biological reactions.

Catalyst and Energy Change

Inhibitors Inhibitors slow down a chemical reaction. Inhibitors bind to a catalyst and prevent it from speeding up a reaction. Ex. Preservation of food. Antioxidants prevent foods from becoming stale or moldy.

Chem II: 4.15.15 Objectives: Review factors that influence speed of reactions. Determine what chemical equilibrium is for reversible reactions. Identify stresses that alter the chemical equilibrium position of a system.

Chemical Reactions Why is it that most chemical reactions do not go to 100% completion?

Chemical Reactions Why is it that most chemical reactions do not go to 100% completion? Most reactions are reversible. Reversible Reactions: The forward and reverse reactions for a system occurs simultaneously. A double arrow is used in an equation that is reversible.

Reversible Reactions What does this graph tell you about reversible reactions? http://www.800mainstreet.com/7/0007-000-ans-selftest.html

Chemical Reactions Why is it that most chemical reactions do not go to 100% completion? Most reactions are reversible. Reversible Reactions: The forward and reverse reactions for a system occurs simultaneously. A double arrow is used in an equation that is reversible.

Chemical Equilibrium When the rates (speed) of the forward and reverse reactions are equal to one another. Does it also mean the concentration of reactants and products are equal? http://www.800mainstreet.com/7/0007-000-ans-selftest.html

Chemical Equilibrium Equilibrium Position: The concentration of reactants and products remain constant. Indicates which direction is most favored. (forward) http://www.fccj.us/chm2046/SampleTest/46M10iAnswers.htm

Chemical Equilibrium What factors can affect chemical equilibrium?

Equilibrium Disturbance Chart Equilibrium Disruption System’s Response (re-establish equilibrium) Effects Equilibrium Constant Change in pressure Change in temperature Change in concentration

Chemical Equilibrium A + B ---------> C + D

Chemical Equilibrium What factors can affect chemical equilibrium? LeChatelier’s Principle:

Chemical Equilibrium What factors can affect chemical equilibrium? -Concentration of substances in the reversible reaction. -Temperature -Pressure LeChatelier’s Principle: -If a stress is exerted on system in equilibrium, the system changes in a way to relieve that stress. -The equilibrium position will change.

Chem II: 4.16.15 Objectives: Review factors that influence speed of reactions. Determine what chemical equilibrium is for reversible reactions. Identify stresses that alter the chemical equilibrium position of a system. Explain (qualitatively/quantitatively) what the value of Keq indicates about the position of equilibrium

Chemical Equilibrium: Bell Ringer 2. Use the graphs below to define chemical equilibrium. http://www.fccj.us/chm2046/SampleTest/46M10iAnswers.htm

Le Chatelier’s Principle: Application

Chem II: 4.21.15 Objectives: Review factors that influence speed of reactions. Identify stresses that alter the chemical equilibrium position of a system. Determine what the chemical equilibrium is for reversible reactions(qualitatively/quantitatively).

Changes in Chemical Equilibrium 1. Using Le Chatelier’s Principle, explain how the equilibrium position of this reaction is affected by the following changes? N2O4(g) + 58J 2NO2(g) Addition of heat Decrease in pressure Addition of NO2 Removal of N2O4(g)

Changes in Chemical Equilibrium 1. Using Le Chatelier’s Principle, explain how the equilibrium position of this reaction is affected by the following changes? N2O4(g) + 58J 2NO2(g) Addition of heat Decrease in pressure Addition of NO2 Removal of N2O4(g)

Chemical Equilibrium Constant What is the chemical equilibrium constant equation? What does the chemical equilibrium constant value indicate about a reversible reaction at equilibrium? Explain your answer with an example.

Chem II: 4.22.15 Objectives: Review factors that influence speed of reactions. Identify stresses that alter the chemical equilibrium position of a system. Determine what the chemical equilibrium is for reversible reactions(qualitatively/quantitatively).

Chemical Equilibrium Constant What is the chemical equilibrium constant equation? What does the chemical equilibrium constant value indicate about a reversible reaction at equilibrium? Explain your answer with an example.

Equilibrium Constants Ratio of product to reactant concentrations at equilibrium, K(eq) Concentration expressed in molarity. aA + bB cC + dD Equilibrium constant identifies which reaction is favored at equilibrium. Keq > 1: Keq <1:

Equilibrium Constants Ratio of product to reactant concentrations at equilibrium, K(eq) Concentration expressed in molarity. aA + bB cC + dD Equilibrium constant identifies which reaction is favored at equilibrium. Keq > 1: favors forward or products Keq <1: favors reverse or reactants No units for equilibrium constant

Chemical Equilibrium Constant What is the chemical equilibrium constant equation? What does the chemical equilibrium constant value indicate about a reversible reaction at equilibrium? Explain your answer with an example.

Calculating Chemical Equilibrium A liter of a gas mixture at equilibrium at 10oC contains 0.0045mol of N2O4 and 0.030 mol of NO2. N2O4 (g) 2NO2 (g) a.Write the expression for the equilibrium constant for the reaction above. b. Calculate the equilibrium constant for the reaction. c. Based on the Keq value, is the product or reactants favored in this reversible reaction? Explain.

Chem II: 4.27.15 Infinite Campus: Le Chatelier’s Application-Gallery Walk Le Chatelier’s and Keq Quiz Objectives: Identify stresses that alter the chemical equilibrium position of a system. (Review) Determine what the chemical equilibrium is for reversible reactions(qualitatively/quantitatively).

Chem II: 4.28.15 Objectives: Identify stresses that alter the chemical equilibrium position of a system. *Make-up Quiz Tomorrow, Wed. Determine what the chemical equilibrium is for reversible reactions(qualitatively/quantitatively). Interpret Ksp values. 

Chem II: 4.29.15 Objectives: Identify stresses that alter the chemical equilibrium position of a system. Make-up Quiz Determine what the chemical equilibrium is for reversible reactions(qualitatively/quantitatively).

Chemical Equilibrium Calculations R=ratio; I=[Initial]; C=[change]; E= [at equilibrium]

Chemical Equilibrium

Chem II: 4.30.15 Infinite Campus: Le Chat and Keq Make-up Quiz Objectives: Identify stresses that alter the chemical equilibrium position of a system. Determine what the chemical equilibrium is for reversible reactions(qualitatively/quantitatively).

Le Chatelier’s Quiz

Chemical Equilibrium Calculations R=ratio; I=[Initial]; C=[change]; E= [at equilibrium]

Chem II: 5.01.15 Due: LeChat and Keq Packet Objectives: Identify stresses that alter the chemical equilibrium position of a system. Determine what the chemical equilibrium is for reversible reactions(qualitatively/quantitatively). Identify and apply Ksp constant. Homework: Exam next Wednesday-begin to review

Spontaneous Reactions and Equilibrium Exam Concepts: Factors that influence the rate of a reaction Energy diagrams(activation eneryg/catalyst) Entropy vs. Enthalpy Classifying spontaneous reactions using Gibbs Free Energy Equation. Chemical Equilibrium Constant, Keq (interpret/apply) Le Chatelier’s Prinple (application) Solubility Equilibrium Constant, Ksp (interpret/apply)

Spontaneous Reactions and Equilibrium Exam Concepts: Factors that influence the rate of a reaction Energy diagrams(activation eneryg/catalyst) Entropy vs. Enthalpy Classifying spontaneous reactions using Gibbs Free Energy Equation. Chemical Equilibrium Constant, Keq (interpret/apply) Le Chatelier’s Prinple (application) Solubility Equilibrium Constant, Ksp (interpret/apply)

Chemical Equilibrium Calculations Worksheet #2 R=ratio; I=[Initial]; C=[change]; E= [at equilibrium]

Chem II: 5.05.15 Due: Infinite Campus updated LeChat and Keq Packet-due today Objectives: Identify stresses that alter the chemical equilibrium position of a system. Determine what the chemical equilibrium is for reversible reactions(qualitatively/quantitatively). Identify and apply Ksp constant. Homework: Exam on Wednesday

Solubility Equilibrium Constant 1. What does the solubility equilibrium constant represent, K(sp). 2. What is the K(sp) equation? 3. What factor(s) influence the K(sp) value?

Solubility Equilibrium Also called solubility equilibrium product, K(sp) : the product of the ions’ concentration values K(sp) expression: Dependent upon temperature Determines the degree of solubility for the compound.

Chem II: 5.05.15 Due: LeChat and Keq Packet-LATE Objectives: Identify stresses that alter the chemical equilibrium position of a system. Le Chat Lab(Tues./Wed.) Determine what the chemical equilibrium is for reversible reactions(qualitatively/quantitatively). Identify and apply Ksp constant. (Tues.) Homework: Exam on Thursday

Solubility Equilibrium Also called solubility equilibrium product, K(sp) : the product of the ions’ concentration values K(sp) expression: Dependent upon temperature Determines the degree of solubility for the compound.

Solubility Equilibrium Constant, Ksp Rank these solutions from least to most soluble(@25oC) Pb(SO4), Ksp: 6.3x10-7 Zn(OH), Ksp: 3.0x10-16 Ca(SO4), Ksp: 2.4x10-5 2.What is the concentration of lead ions and chromate ions in a saturated lead chromate,Pb(CrO4) solution at 25oC? Ksp(PbCrO4) = 1.8x10-14 3. What is the concentration of magnesium ions and hydroxide ions in a saturated magnesium hydroxide solution, Mg(OH)2? KspMg(OH)2 =7.1x10-12

Solubility Equilibrium Constant, Ksp Rank these solutions from least to most soluble(@25oC) Pb(SO4), Ksp: 6.3x10-7 Zn(OH), Ksp: 3.0x10-16 Ca(SO4), Ksp: 2.4x10-5 2.What is the concentration of lead ions and chromate ions in a saturated lead chromate,Pb(CrO4) solution at 25oC? Ksp(PbCrO4) = 1.8x10-14 3. What is the concentration of magnesium ions and hydroxide ions in a saturated magnesium hydroxide solution, Mg(OH)2? KspMg(OH)2 =7.1x10-12

Le Chatelier’s Principle Lab Purpose: Hypothesis: Predict how the system will react to the stresses applied to test tubes #2-4. What is the purpose of the control(test tube number one) in this experiment?

Le Chatelier’s Principle Lab Purpose: Hypothesis: Predict how the system will react to the stresses applied to test tubes #2-4. What is the purpose of the control(test tube number one) in this experiment?

Chem II: 5.11.15 Due: Le Chat Lab-13 pts. Objectives: Identify stresses that alter the chemical equilibrium position of a system. Determine what the chemical equilibrium is for reversible reactions(qualitatively/quantitatively). Identify and apply Ksp constant. Homework: Exam on Wednesday

Le Chat Lab

Chem II: Reaction Rates and Equilibrium (11.14) Objectives: Review factors that influence speed of reactions. Determine what chemical equilibrium is for reversible reactions. Identify stresses that alter the chemical equilibrium position of a system. Explain (qualitatively/quantitatively) what the value of Keq indicates about the position of equilibrium Interpret solubility equilibrium.

Equilibrium Disturbance: Pressure N2O4(g) + 58J ---> 2NO2(g) apchem09.wikispaces.com

Changes in Chemical Equilibrium 1. Using Le Chatelier’s Principle, explain how the equilibrium position of this reaction is affected by the following changes? N2O4(g) + 58J 2NO2(g) Addition of heat Decrease in pressure Addition of NO2 Removal of N2O4(g) Can a pressure change shift the equilibrium position in every reversible reaction? Explain your answer. a. What is a chemical equilibrium constant? b. What can it tell you about a reversible reaction?

Calculating Chemical Equilibrium Constants 7. The reversible reaction: N2(g) + 3H2(g) -----> 2NH3(g) produces ammonia which is a fertilizer. At equilibrium, a 1-L flask contains 0.15 mol H2, 0.25 mol N2, and 0.10molNH3. Write the expression for the equilibrium constant for the reaction? b. Calculate the Keq for the reaction. c. Based on the Keq value, is the product or reactants favored in this reversible reaction? Explain.

Calculations with Chemical Equilibrium Constants Gallery Walk of Homework Questions. Extra practice problems: 16., 51., 52.

Chem II: Reaction Rates and Equilibrium (11.15) Objectives: Review factors that influence speed of reactions. Determine what chemical equilibrium is for reversible reactions. Identify stresses that alter the chemical equilibrium position of a system. Explain (qualitatively/quantitatively) what the value of Keq indicates about the position of equilibrium Interpret solubility equilibrium.

Chem II: Reaction Rates and Equilibrium (11.16) Infinite Campus Update: Chemical Equilibrium Quiz Objectives: Review factors that influence speed of reactions. Determine what chemical equilibrium is for reversible reactions. Identify stresses that alter the chemical equilibrium position of a system. Explain (qualitatively/quantitatively) what the value of Keq indicates about the position of equilibrium Interpret solubility equilibrium constant. Interpreting rate laws and predicting reaction orders.

Reversible Reactions Can you think of a reaction that is not reversible?

Reversible Reactions Can you think of a reaction that is not reversible? Formation of a gas if produced in an open container. Formation of insoluble or slightly soluble products. NaCl (aq) + AgNO3(aq) -----> NaNO3 (aq) + AgCl(s)

Solubility Equilibrium 1. What is the solubility equilibrium constant? 2. What does the solubility equilibrium constant tell you? 3. Why does doctors give patients barium sulfate solution for X-ray analysis when the ions are toxic to our blood stream?

Solubility Equilibrium Also called solubility equilibrium product, K(sp) : the product of the ions’ concentration values K(sp) expression: Dependent upon temperature Determines the degree of solubility for the compound.

Solubility Equilibrium Calculations Ex. What is the concentration of barium ions and sulfate ions in a saturated barium sulfate solution at 25oC. a. Write out the solubility equation for barium sulfate. b. What is the Ksp expression for barium sulfate solution? c. What is the Ksp constant for barium sulfate solution at 25oC. Pg. 562

Chem II: Reaction Rates and Equilibrium (11.19) Infinite Campus Update: Chemical Equilibrium Quiz Soda Can Lab Report (29pts.) Heats of Reaction Report (15pts.) Objectives: Interpret solubility equilibrium constant. Interpreting rate laws and predicting reaction orders.

Solubility Equilibrium Calculations Practice problems: 18.3, 17, 18 (pg. 562)

Common Ion Effect PbCrO4 (s) ---> Pb2+ (aq) + CrO42- (aq), Ksp = 1.8x10-14 What would happen if you add Pb(NO3)2 to the solution at equilibrium?

Common Ion Effect Common ions: each salt in the solution has a common (the same) ion. Common ion effect: Solubility is lowered for one of the salts in the solution. Ex. Adding sodium sulfate to barium sulfate solution further decreases the solubility of barium sulfate in solution.

Common Ion Effect Ex. The solubility product constant of AgBr is 5.0x10-13. What is the bromide-ion concentration of a 1.00L saturated solution of AgBr to which 0.020 mol of Ag(NO3) is added?

Solubility Equilibrium Calculations

Predicting Solubility: Double Replacement Reactions Can predict the solubility of substances produced from a double replacement reaction. Ex. Will barium sulfate precipitate when 0.5 L of 0.002M Ba(NO3)2 reacts with 0.50 L of 0.008 M Na2(SO4) to form a 1L solution? The Ksp of Ba(SO4) is 1.1x10-10.

Predicting Solubility Predict whether calcium carbonate will precipitate when 0.5 L of 0.001M Ca(NO3)2 is mixed with 0.5 L of 0.008M Na2(CO3) to form 1L of solution. The Ksp of CaCO3 is 4.5x10-9.

Chem II: Reaction Rates and Equilibrium (11.19) Objectives: Interpret solubility equilibrium constant. Quiz over solubility equilibrium problems Predicting solubility of products from a double replacement reaction. Interpreting rate laws and predicting reaction orders.

Additional Practice Problems Predicting Solubility: Questions 6 and 7:

Predicting Solubility Practice Problems Key Yes, AgCl because product of ions= 1.0x10-4 > Ksp of AgCl = 8.3x10-17. 11.Yes, CaCO3 product of ions= 2x10-7 > Ksp of CaCO3 = 4.5x10-9

Chem II: Reaction Rates and Equilibrium (11.25) Objectives: Review factors that influence speed of reactions. Determine what chemical equilibrium is for reversible reactions. Identify stresses that alter the chemical equilibrium position of a system. Explain (qualitatively/quantitatively) what the value of Keq indicates about the position of equilibrium Interpret solubility equilibrium constant.

Predicting Solubility: Double Replacement Reactions 6a. Predict whether a precipitate will form in the solution? Ba2+= 0.02M, F1- = 0.0015M; actual Ksp= 1.0x10-6

Gallery Walk: Reaction Rates and Equlibrium Lab Bench Practice Problem Question 1 # 2 2 #4 3 #5 4 #7 5 qts. on bench 6

Gallery Walk: Reaction Rates and Equlibrium Lab Bench Practice Problem Question 1 # 2 2 #4 3 #5 4 #7 5 qts. on bench 6

Chemistry II: Foods Day Name Food

Chemistry II: 12.2 Objectives: Schedule make-up exams for this week. Interpreting rate laws and predicting reaction orders. Homework: Rate Law Problems

Chemical Reaction Rates

Rate Law An expression that connects reaction rates with concentration of reactants. A + B ----->AB R = k [A]n[B]m

Rate Law Constant (k) R = k [A]n[B]m What is the rate law constant (k) dependent upon?

Reaction Orders Exponents in the rate law expression. R = k [A]n[B]m Each reactant has an exponent. It identifies a possible relationship between a reactant’s concentration and the reaction rate. Order of Reaction = sum of orders in reaction (n+m)

Reaction Orders Exponents are small integers in the rate law expression. R = k [A]n [B]m Reaction orders are NOT coefficients from a balanced equation. Determined only from experimental data. [A]0 = rate change does not depend upon concentration change of reactant. [A]1 = rate change is directly proportional to concentration change of reactant. [A]2 = rate change is directly proportional to the square of the concentration change of reactant. [A]3 = rate change is directly proportional to the cube of the concentration change of the reactant.

Rate Law Expressions

Rate Law Three experiments that have identical conditions were performed to measure the initial rate of the reaction. 2HI(g) ----> H2(g) + I2(g) Experimental Results: Experiment [HI] Molar Rate (M/s) 1 0.015 1.1x10-3 2 0.030 4.4x10-3 3 0.045 9.9x10-3 a. Write the rate law for this reaction.

Rate Law Three experiments that have identical conditions were performed to measure the initial rate of the reaction. 2HI(g) ----> H2(g) + I2(g) Experimental Results: Experiment [HI] Molar Rate (M/s) 1 0.015 1.1x10-3 2 0.030 4.4x10-3 3 0.045 9.9x10-3 Use the rate law expression to calculate the rate constant for this reaction.

Chemistry II: 12.3 Objectives: Establishing and interpreting rate laws by predicting reaction orders of reactants. Homework: Rate Law problems Rate Law Lab: Read and complete pre-lab questions

Chemistry II: Rate Laws a. What is a rate law? b. How is it useful to chemists? 2. A + B -----> C Write the rate law expression for this reaction. From experimental data, it was observed that as [A] doubles the reaction rate doubles. As[B] doubles the reaction rate does not change. Determine the order of each reactant and add it to your rate expression above. What is the overall reaction order for this reaction? a. Identify a factor that affects the rate constant, k. b. Identify a factor that does NOT affect the rate constant,k.

Rate Law Practice Problems

Rate Law Calculations Three experiments were performed to measure the initial rate of the reactions. A + B -----> C Experimental Results: Only concentrations varied with each experiment Experiment [A] Molar [B] Molar Rate (M/s) 1 1.2 2.4 8.0x10-8 2 4.0x10-8 3 3.6 7.2x10-7 What units are associated with concentration? What units are associated with reaction rate? Determine the reaction order for each reactant. What is the overall order for this reaction? Write the rate law expression for this reaction. Calculate the rate constant,k, for this reaction.

Rate Law Three experiments were performed to measure the initial rate of the reactions. A + B -----> C Experimental Results: Only concentrations varied with each experiment Experiment [A] Molar [B] Molar Rate (M/s) 1 1.2 2.4 8.0x10-8 2 4.0x10-8 3 3.6 7.2x10-7

Chemistry II: 12.4 Due: Rate Law Practice Problems Worksheet Objectives: Establishing and interpreting rate laws by predicting reaction orders of reactants. Set-up Rate Law Lab Homework: Rate Law Quiz tomorrow-review notes/practice problems Be prepared for Rate Law Lab

Rate Law Problems: Gallery Walk Gallery walk designed to promote peer collaboration and feed-back. Write your group’s answer on white board. Transfer your answer to the paper-will collect as evidence of your participation in walk. Will rotate twice so that you can assess two other group’s problems. Record your answer for those problems as well on paper that will be collected.

Chemistry II: 12.5 Objectives: Establishing and interpreting rate laws by predicting reaction orders of reactants. Rate Law Quiz Complete Rate Law Lab Homework: Complete post-lab questions and work on lab report.

Rate Law Lab Review background and procedure sections from modified version. Complete pre-lab questions. Show work for one experiment. Lab Groups: Collect and ensure lab equipment is clean. Discuss pre-lab answers. Complete lab-follow modified version Complete post-lab questions 4. Work on Lab Report-Due Monday

Rate Law Lab Materials Modification: watch glass instead of reaction plates Refer to each trial as an experiment instead of well #, because NOT using reaction plates. small graduated cylinders instead of syringes. plastic pipettes paper towels instead of cotton swabs

Chemistry II: 12.5 Objectives: Establishing and interpreting rate laws by predicting reaction orders of reactants. Complete Rate Law Lab Homework: Complete post-lab questions and work on lab report.

Chemistry II: 12.9 Infinite Campus Update: Chemical Reaction Rate/Equilibrium Exam (39pts.) Rate Law Gallery Walk (6pts.) Interpreting Rate Law Graph (10pts.) Rate Law Quiz (16pts.) Objectives: Establishing and interpreting rate laws by predicting reaction orders of reactants. Complete Rate Law Lab Homework: Post Lab questions and Lab Report-due Wed. Check Infinite Campus for missing assignments.

Chemistry II: 12.10 Objectives: Establishing and interpreting rate laws by predicting reaction orders of reactants. Analyze Rate Law Lab data Distinguishing between three definitions of Acids/Bases Homework: Rate Law Lab Report-due Wed.

Rate Law Lab Data Lab Group Rate Order Na2(S2O3) HCl

Rate Law Lab Report Your lab report needs to include the following headings: Purpose: brief summary-paragraph Materials: bullet of materials/stock solutions No hypothesis with this lab Data: Qualitative (paragraph) and Quantitative (tables) Analysis: (paragraph format) Conclusion: (paragraph format)

Rate Law Lab: Interpreting Data Think about what two experiments would yield the most accurate reaction order for each reactant. Can repeat experiments if reaction order is not obvious. Can validate reaction orde by graphing concentration of each reactant vs. time.

Validate Reaction Order of Reactants [A] versus t (linear for a zero order reaction) ln [A] versus t (linear for a 1st order reaction) 1 / [A] versus t (linear for a 2nd order reaction) http://www.chem.purdue.edu/gchelp/howtosolveit/Kinetics/IntegratedRateLaws.html

Rate Law Quiz

Chemical Equilibrium Exam Make-up Exam Date

Acids/Bases Chpt. 15 (purple textbook) Acid/Base compounds have been defined three ways. Identify and distinguish between the three definitions of acids/bases. Identify and explain which definition is best for chemist.

Chemistry II: 12.11 Objectives: Identifying the three definitions of acids and bases. Homework: Rate Law Lab Report-due Thursday Organizing notes, unit exams, and quizzes for final next week. Study guide will be issued tomorrow.

Homework Check-up: Defining Acids and Bases Use your homework to define/illustrate the following: Arrhenius Acids and Bases Bronsted-Lowery Acids and Bases Lewis Acids and Bases

Acids and Bases Arrhenius Acids and Bases:

Acids and Bases Arrhenius Acids and Bases: Acids: Compounds that give off H+ ions in aqueous solutions. Bases: Compounds that give off OH- ions in aqueous solutions.

Acids and Bases: pH scale

Strong vs Weak Acids and Bases Strong Acids/Bases: Dissociates 100% in solution. Wead Acids/Bases: Dissocates less than 5% in solution. Weak Acid: HNO2 Strong Acid: HCl www.chem.wisc.edu 

Strong vs. Weak Acids Acid: Chemical Formula Solubility in Water Strong or Weak Acid hydrochloric: HCl high sulfuric: H2(SO4) Phosphoric: H3(PO4) low Nitric : H(NO3) Carbonic: H2(CO3) The degree of dissociation or solubility is based on how polar the chemical bond is between hydrogen and the other substance. If bonded to a very electronegative element or substance then it will dissociate easily in water. Ex. H----Cl vs. H-----(NO3)

Dissociation of HCl in water en.wikipedia.org

Molecules and Polarity Polar Molecules: Do not share electrons equally because one element has a greater pull on electrons making up bond. Ex. O----H (between different non-metals) Non-Polar Molecules: Share electrons equally because each element has same pull on bonded electrons. Ex. H-----H (Diatomic molecules. )

Electronegativity: “pull” on bonded electrons

Dissociation of HCl in water en.wikipedia.org

Strong vs. Weak Bases Bases Solubility Strong vs. Weak Bases K(OH) high Na(OH) Ca(OH)2 Mg(OH)2 low Metals degree of reactivity with water determines its solubility and strength. Metals from group one are most reactive (most soluble) with water, so are the strongest bases.

Defining Acids and Bases Bronsted-Lowery Acids and Bases:

Defining Acids and Bases Bronsted-Lowery Acids and Bases: Acids: Hydrogen ion donor Base: Hydrogen ion acceptor Example: Ammonia (NH3) is classified as a base when dissolved in water, why?

Defining Acids and Bases Bronsted-Lowery Acids and Bases: Acids: Hydrogen ion donor Base: Hydrogen ion acceptor Example 1: Ammonia (NH3) is classified as a base when dissolved in water, why? NH3(aq) + H2O (l) ----> NH4 (aq) + OH- (aq) (base) (acid) (conjugate acid) (conjugate base)

Conjugate Acid-Base Pair Bronsted-Lowery Acids and Bases: Acids: Hydrogen ion donor Base: Hydrogen ion acceptor *With reversible reactions identified conjugate acid-base pairs. *Conjugate acid-base pairs: Two substances in a reversible reaction that are related to one another by the loss or gain of a H+ ion. NH3(aq) + H2O (l) ----> NH4 (aq) + OH- (aq) (base) (acid) (conjugate acid) (conjugate base)

Conjugate Acid-Base Pair Bronsted-Lowery Acids and Bases: Acids: Hydrogen ion donor Base: Hydrogen ion acceptor *With reversible reactions identified conjugate acid-base pairs. Example2: HCl is an acid when dissolved in water, why?

Conjugate Acid-Base Pair What is interesting about water in our Bronsted-Lowery Acid/Base examples below? Ex.1: NH3(aq) + H2O (l) ----> NH4 (aq) + OH- (aq) (base) (acid) (conjugate acid) (conjugate base) Ex.2: HCl(aq) + H2O (l) ----> Cl- (aq) + H3O+ (aq) (acid) (base) (conjugate base) (conjugate acid)

Defining Acids/Bases Lewis Acids and Bases:

Defining Acids/Bases Lewis Acids and Bases: Lewis Acid: Accepts a pair of electrons during covalent bonding. Lewis Base: Donates a pair of electrons during covalent bonding. Example:

Chemistry II: 12.12 Objectives: Scholastic Reading Inventory (SRI) Assessment Identifying and applying the three definitions of acids and bases. I can assess the strength of an acid or base using the acid dissociation constant. Homework: Rate Law Lab Report-due Thursday Organizing notes, unit exams, and quizzes for final next week. Study guide will be issued tomorrow.

Defining Acids/Bases Lewis Acids and Bases: Lewis Acid: Accepts a pair of electrons during covalent bonding. Lewis Base: Donates a pair of electrons during covalent bonding. Example:

Chemistry II: 12.13 Objectives: Identifying and applying the three definitions of acids and bases. I can assess the strength of an acid or base using the acid dissociation constant. Homework: Rate Law Lab Report-due Today Organizing notes, unit exams, and quizzes for final next week. Study guide will be issued tomorrow.

ChemII: 12.16.13 Due: Rate Law Lab: -late but will accept for partial credit. Objectives: Identifying and applying the three definitions of acids and bases. I can assess the strength of an acid or base qualitatively. Review for Final Exam Homework: Organize unit exams, review study guide and notes. Power points are on my webpage. Study guide session available after school tomorrow. Check infinite campus for missing work, etc.

Defining Acids/Bases Acid/Base Theories Acid Base Arrhenius H+ producer OH- producer Bronsted-Lowry H+ donor H+ acceptor Lewis Electron-pair acceptor Electron-pair donor

Lewis Acids and Bases

Acid/Base Text Problems

Strength of Acids and Bases

ChemII: 12.17.13 Due: Rate Law Lab: -late but will accept for partial credit. Objectives: Identifying and applying the three definitions of acids and bases. I can assess the strength of an acid or base qualitatively. Review for Final Exam Homework: Organize unit exams, review study guide and notes. Power points are on my webpage. Study guide session available after school tomorrow. Check infinite campus for missing work, etc.

Strength of Acids and Bases Is the strength of an acid/base dependent upon concentration of solute or dissociation of solute? Explain.

Acid/Base Equilibrium Expression Concentration ratio of products vs. reactants Example: Keq = If Keq is large, will it be a strong or weak acid/base? If Keq is small, will it be a strong or weak acid/base?

Final Exam Study Guide

Equilibrium Expression In diluted solutions, H2O is constant and not apart of the expression. Concentration ratio of the products to acid/base reactant. Example of an Acid CH3COOH (aq) + H2O(l) ---> CH3COO- (aq) + H3O+ (aq) Example of a Base: NH3(aq) + H2O (l) ----> NH4 (aq) + OH- (aq)

Weak Acids: Dissociation Constants For weak acids, can use experimental data to calculate the dissociation constant. Ex. A 0.100M solution of ethanoic acid is only partially ionized. From measurements of the pH of the solution [H+] is determined to be 1.34x10-3 M. What is the acid dissociation constant, Ka, of ethanoic acid.