UNIT 3: CHEMICAL EQUILIBRIUM (TEXT: Chap 14-pg 627 & Chap 18 pg )
|
|
- Polly Eaton
- 5 years ago
- Views:
Transcription
1 UNIT 3: CHEMICAL EQUILIBRIUM (TEXT: Chap 14-pg 627 & Chap 18 pg ) *Remedial questions on Concentration of Solutions (3.10 pg ) 3:1. ATTEMPT QUESTIONS a) b) c) d) on Page 146 3:2. What volume of 12 M HCl must be added to 1.0 L of 0.1 M HCl so that the resulting sol'n will be 0.5 M? [ Hint : take "x" litres of 12 M HCl] (34.8 ml) 3:3. 15 ml of 0.5 M NaCl & 60 ml of 0.5 M KCl are mixed together. Find the concentrations of each ion in the sol'n. ( [Na + ]=0.1, [K + ]=0.4, [Cl ] = 0.5 M ) 3.4. Practice questions on working out equilibrium concentrations a) A + B AB b) A + B AB c) A 2 + B 2 2 AB d) A 2 + B 2 2AB [in] [in] [in] [in] [Eq] [Eq] [Eq] [Eq] e) A 2 + B 2 2 AB f) A 2 + B 2 2 AB g) 2A + B A 2 B h) 2A + B A 2 B [in] [in] [in] [in] [Eq] [Eq] [Eq] [Eq] i) 2A + B 2 2 AB j) 2A + B 2 2 AB k) 2AB 3 A 2 + 3B 2 l) 2AB 3 A 2 + 3B 2 [in] [in] [in] [in] [Eq] [Eq] [Eq] [Eq] m) 2AB 3 A 2 + 3B 2 n) 2AB 3 A 2 + 3B 2 o) 2AB 3 A 2 + 3B 2 p) 2AB 3 A 2 + 3B 2 [in] [in] [in] [in] [Eq] [Eq] [Eq] [Eq] *LeChatelier's Principle. (14.8 pg ) 3.5. ATTEMPT QUESTIONS a) 15 (pg 660) b) c) d) e) on Page 661 f) (pg 664) 3:6. SO 2 (g) + ½O 2 (g) SO 3 (g) kj Discuss the conditions that would favour a high eq'm conc of SO 3 (g). 3:7. Explain,using LeChatelier's Principle, why increasing the pressure on boiling water causes it to stop boiling until a higher temperature is reached. What kitchen utencil relies on this notion? H 2 O (l) H 2 O (g) H rx = + 44 kj 3:8. MnCl 2 has a fairly low solubility in water ( 2.6 g/100 ml). Using LeChatelier's Princilple would you expect the solubility to be any better in a solution of 1 M NaCl.(write the chemical equations out) ( known as the Common Ion Effect ) *The Law of Chemical Equilibrium (14.3 pg ) 3.9. Attempt question a) 14.8 b) c) d) e) f) g) on page :10. The following system is at eq'm : NH 4 NO 3 (s) 2 H 2 O (g) + N 2 O (g) a) Write the Ke expression b) If the [ H 2 O ] was tripled what would happen to [ N 2 O ]? c) If the [ N 2 O ] was reduced by 16 X what would happen to [ H 2 O ]?
2 *Calculating the equilibrium constant ( Ke or Kc) (14.9 pg ) Attempt questions a) b) c) d) e) on page 663 in your text 3:12. Consider this eq'm : PCl 5 (g) + H 2 (g) 2 HCl (g) + PCl 3 (g) in a 2 L vessel, at eq'm, there were 2 mol of PCl 5 (g), 2 mol of H 2 (g),6 mol of HCl and 2 mol of PCl 3 (g) a) Calculate Ke for this rx. b) Calculate Ke for the reverse rx. 3:13. A rx'n occurs according to this equation : A (g) + 2 B (g) 2 C (g) * 3 mol of A and 5 mol of B are reacted in a 3 L container. After equilibrium had been reached 1 mol of A remained in the container. Calculate Ke for the rx. 3:14. Attempt questions a) b) c) d) on page 663 *Using the equilibrium constant ( Ke or Kc) to calculate eq m concentrations (14.9 pg ) 3:15. Given : Pb 2+ (aq) + Sn (s) Sn 2+ (aq) + Pb (s) ; Ke = 1.2 * If 0.1 mol of lead nitrate is dissolved in 200 ml of water and a chunk of solid tin added, find the eq'm concentrations of both metallic ions. 3:16. Attempt questions a) b) c) on page 663 ( all perfect squares) 3:17. For the reaction : CO 2 (g) + H 2 (g) CO (g) + H 2 O (g) Ke = 0.02 Suppose that 22 g of CO 2 and 2 g of H 2 are placed in a 2.0 L container. Find the eq'm concentrations of all species and plot a rough conc - time graph. 3:18. Attempt questions a) b) on page 664 ( use the quadratic eq n) 3:19. The following system was allowed to reach eq'm : SO 3 (g) + NO (g) NO 2 (g) + SO 2 (g) The 1st eq'm concentrations were : [NO 2 ] eq m = 0.8 M, [SO 2 ] = 0.12 M, [NO] = 0.4 M, & [SO 3 ] = 0.48 M * NOW an additional 0.52 M SO 3 was added to the system, determine the 2nd eq'm concentrations of all species at this new eq'm state and plot a rough conc - time graph. *Free Energy ( G ) and Equilibrium (18.8 pg 818) Attempt questions a) b) c) d) on page 840 in your text 3:21. Using your data sheet calculate G and then Ke for the reaction 2 NO (g) + 2 CO (g) N 2 (g) + 2 CO 2 (g) at 500 C. 3:22. Consider this reaction : CO (g) + 1/2 O 2 (g) CO 2 (g) a) Calculate G and Ke for the rx at 300 C b) Calculate the temp at which G =0. What is Ke at this temp? c) Discuss the temp range of spontaneity for the rx
3 Chemical Equilibrium: Finding a Constant, Ke ( Kc ) The purpose of this lab is to experimentally determine the equilibrium constant, Kc, for the following chemical reaction: Fe 3+ aq) + SCN - (aq) FeSCN 2+ (aq) iron(iii) thiocyanate ferrocyanate ion When Fe 3+ and SCN - are combined, equilibrium is established between these two ions and the FeSCN 2+ ion. In order to calculate Kc for the reaction, it is necessary to know the concentrations of all ions at equilibrium: [FeSCN 2+ ]eq, [SCN - ]eq, and [Fe 3+ ]eq. You will prepare four equilibrium systems containing different concentrations of these three ions. The equilibrium concentrations of the three ions will then be experimentally determined. These values will be substituted into the equilibrium constant expression to see if Kc is indeed constant. In order to determine [FeSCN 2+ ] eq, you will use the colorimeter shown in Figure 1. The FeSCN 2+ ion produces solutions with a red color. Because the red solutions absorb blue light very well, the blue LED setting on the colorimeter is used. The computer-interfaced colorimeter measures the amount of blue light absorbed by the colored solutions (absorbance, A). By comparing the absorbance of each equilibrium system, Aeq, to the absorbance of a standard solution, Astd, you can determine [FeSCN 2+ ]eq. The standard solution has a known FeSCN 2+ concentration. To prepare the standard solution, a very large concentration of Fe 3+ will be added to a small initial concentration of SCN - (hereafter referred to as [SCN - ]i. The [Fe 3+ ] in the standard solution is 100 times larger than [Fe 3+ ] in the equilibrium mixtures. According to LeChatelier's principle, this high concentration forces the reaction far to the right, using up nearly 100% of the SCN - ions. According to the balanced equation, for every one mole of SCN - reacted, one mole of FeSCN 2+ is produced. Thus [FeSCN 2+ ]std is assumed to be equal to [SCN - ]i. Assuming [FeSCN 2+ ] and absorbance are related directly (Beer's Law), the concentration of FeSCN 2+ for any of the equilibrium systems can be found by: [FeSCN 2+ ]eq = A eq Astd X [FeSCN2+ ]std Knowing the [FeSCN 2+ ] eq allows you to determine the concentrations of the other two ions at equilibrium. For each mole of FeSCN 2+ ions produced, one less mole of Fe 3+ ions will be found in the solution (see the 1:1 ratio of coefficients in the equation on the previous page). The [Fe 3+ ] can be determined by: [Fe 3+ ]eq = [Fe 3+ ]i [FeSCN 2+ ]eq Because one mole of SCN - is used up for each mole of FeSCN 2+ ions produced, [SCN - ] eq can be determined by: [SCN - ]eq = [SCN - ]i [FeSCN 2+ ]eq Knowing the values of [Fe 3+ ] eq, [SCN - ] eq, and [FeSCN 2+ ] eq, you can now calculate the value of K c, the equilibrium constant. PROCEDURE 1. Pipet 5.0 ml of M Fe(NO 3 ) 3 into each of 4 labeled test tubes. CAUTION: Fe(NO 3 ) 3 solutions in this experiment are prepared in 1.0 M HNO 3 and should be handled with care. 2. Pipet 2, 3, 4 and 5 ml of M KSCN into tubes 1-4, respectively. Then pipet 3, 2, 1 and 0 ml of distilled water into tubes 1-4, respectively, to bring the total volume of each test tube to 10 ml. Mix each solution thoroughly with a stirring rod. Be sure to clean and dry the stirring rod after each mixing. Measure and record the temperature of one of the above solutions to use as the temperature for the equilibrium constant, Kc. Volumes added to each test tube are summarized below: Test Tube Number Fe(NO 3 ) 3 (ml) KSCN (ml) H 2 O (ml) Prepare a standard solution of FeSCN 2+ by pipetting 18 ml of M Fe(NO 3 ) 3 into a test tube labeled 5. Pipet 2 ml of M KSCN into the tube. Stir thoroughly.
4 3. You are now ready to calibrate the colorimeter. Prepare a blank by filling a cuvette 3/4 full with distilled water. To correctly use a colorimeter cuvette, remember: All cuvettes should be wiped clean and dry on the outside with a tissue. Handle cuvettes only by the top edge of the ribbed sides. All solutions should be free of bubbles. Always position the cuvette with its reference mark facing toward the white reference mark to the right of the cuvette slot on the colorimeter. Choose Calibrate from the Experiment menu and then click Perform Now. Place the blank cuvette in the cuvette slot of the colorimeter and close the lid. Turn the wavelength knob of the colorimeter to the 0% T position. In this position, the light source is turned off, so no light is received by the photocell. Type 0 in the % edit box. When the displayed voltage reading for Input 1 stabilizes, click Keep. For Reading 2, turn the wavelength knob of the colorimeter to the Blue LED position (470 nm). In this position, the colorimeter is calibrated to show 100% of the blue light being transmitted through the blank cuvette. Type 100 in the % edit box. When the displayed voltage reading for Input 1 stabilizes, click Keep., then click OK. 4. You are now ready to collect absorbance data for the four equilibrium systems and the standard solution. Click Collect. Empty the water from the cuvette and rinse it twice with ~1-mL portions of the Test Tube 1 solution. Then fill the cuvette 3/4 full with the solution from Test Tube 1. Wipe the outside of the cuvette with a tissue and then place the cuvette in the colorimeter. After closing the lid, wait for the absorbance value displayed in the Meter window to stabilize. Then click Keep, type 1 (the trial number) in edit box, and press the ENTER key. 5. Discard the cuvette contents & rinse the cuvette twice with the Test Tube 2 solution and fill the cuvette 3/4 full. Follow the procedure in Step 6 to find and record the absorbance of this solution. Type 2 in the edit box and press ENTER. 6. Repeat the Step 6 procedure to find the absorbance of the solutions in Test Tubes 3, 4, and 5 (the standard solution). 7. From the Table window, record the absorbance values for each of the five trials in your Data and Calculations table. PROCESSING THE DATA 1. In the Data and Calculations table, write the K c expression for the reaction. 2. Calculate the initial concentration of Fe 3+, based on the dilution that results from adding KSCN solution and water to the original M Fe(NO 3 ) 3 solution. See Step 2 of the procedure for the volume of each substance used in Trials 1-4. Calculate [Fe 3+ ] i using the equation: [Fe 3+ ]i = Fe(NO 3)3 ml X ( M) This should be the same for all four test tubes. total ml 3. Calculate the initial concentration of SCN -, based on its dilution by Fe(NO 3 ) 3 and water: [SCN - KSCN ml ]i = X ( M) total ml In Test Tube 1, [SCN - ]i = (2 ml / 10 ml)(.0020 M) = M.. 4. [FeSCN 2+ ] eq is calculated using the formula: [FeSCN 2+ ]eq = A eq Astd X [FeSCN2+ ]std where A eq and A std are the absorbance values for the equilibrium and standard test tubes, respectively, and [FeSCN 2+ ] std = (1/10)(0.0020) = M. Calculate [FeSCN 2+ ] eq for each of the four trials. 5. [Fe 3+ ] eq : Calculate the concentration of Fe 3+ at equilibrium for Trials 1-4 using the equation: [Fe 3+ ]eq = [Fe 3+ ]i [FeSCN 2+ ]eq 6. [SCN - ] eq : Calculate the concentration of SCN - at equilibrium for Trials 1-4 using the equation: [SCN - ]eq = [SCN - ]i [FeSCN 2+ ]eq 7. Calculate Kc for Trials 1-4. Be sure to show the Kc expression and the values substituted in for each of these calculations. 8. Using your four calculated K c values, determine an average value for K c. How constant were your K c values?
5 DATA and CALCULATIONS ( show all your work in the space provided) Absorbance Trial 1 Trial 2 Trial 3 Trial 4 Absorbance of standard (Trial 5) Temperature C K c expression K c = [Fe 3+ ] i [SCN - ] i [FeSCN 2+ ] eq [Fe 3+ ] eq [SCN - ] eq K c value Average of K c values K c = at C
6 Assignment:EQUILIBRIUM(1) 1.For the system 2 SO 2 (g) + O 2 (g) 2 SO 3 (g) H is negative for the production of SO 3 Assume that one has an equilibrium mixture of these substances. Predict the effect of each of the following changes on the number of moles of SO 3 and on the value of the equilibrium constant. Briefly account for each of your predictions. (a) Decreasing the volume of the system. (b) Adding oxygen to the equilibrium mixture. (c) Raising the temperature of the system. 2. Sulfuryl chloride, SO 2 Cl 2, is a highly reactive gaseous compound. When heated, it decomposes as follows: SO 2 Cl 2 (g) SO 2 (g) + Cl 2 (g). This decomposition is endothermic. A sample of grams of SO 2 Cl 2 is placed in an evacuated 1.00 litre bulb and the temperature is raised to 375K. (a) What would be the pressure of this gas (in kpa) in the bulb if no dissociation of the SO 2 Cl 2 (g) occurred? (use PV=nRT) (b) When the system has come to equilibrium at 375K, the total pressure in the bulb (the sum of all the partial pressures of all the gases present) is found to be 145 kpa. Calculate the partial pressures of SO 2, Cl 2, and SO 2 Cl 2 at equilibrium at 375K. (recall Daltons Law of partial pressures) (c) Write the equilibrium constant expression for the decomposition of SO 2 Cl 2 (g) at 375K. Calculate the value of the equilibrium constant (K P ) for this rx. (d) If the temperature were raised to 500K, what effect would this have on the equilibrium constant? Explain briefly. 3. CO 2 (g) + H 2 (g) H 2 O (g) + CO (g) When H 2 (g) is mixed with CO 2 (g) at 2000 K, equilibrium is achieved according to the equation above. In one experiment, the following equilibrium concentrations were measured. [H 2 ] = 0.20 mol/l [CO 2 ]= 0.30 mol/l [H 2 O] = [CO] = 0.55 mol/l (a) Using the equilibrium concentrations given, calculate the value of K e for the reaction. (b) When the system is cooled from 2000 K to a lower temperature, 30.0 percent of the CO(g) is converted back to CO 2 (g). Calculate the value of K e at this lower temperature. (c) In a different experiment, 0.50 mole of H 2 (g) is mixed with 0.50 mole of CO 2 (g) in a 3.0-liter reaction vessel at 2000 K. Calculate the equilibrium concentration, in moles per liter, of CO(g) at this temperature. 4. a) Do question on page 665 b) Draw a rough conc vs time graph to represent the changes that took place in this question. 5. NO (g) + 1/2 O 2 (g) NO 2 (g) a) Calculate G and Ke for this 200 C b) Calculate the temperature at which G=0 or Ke=1 and comment on the spontaneity of this reaction and its temperature range
Chemical Equilibrium: Finding a Constant, Kc
Chemical Equilibrium: Finding a Constant, Kc Experiment 20 The purpose of this lab is to experimentally determine the equilibrium constant, K c, for the following chemical reaction: Fe 3+ (aq) + SCN -
More informationChemical Equilibrium: Finding a Constant, Kc
Chemical Equilibrium: Finding a Constant, Kc Experiment 20 The purpose of this lab is to experimentally determine the equilibrium constant, K c, for the following chemical reaction: Fe 3+ (aq) + SCN (aq)
More informationChemical Equilibrium: Finding a Constant, Kc
Chemical Equilibrium: Finding a Constant, Kc Computer 20 The purpose of this lab is to experimentally determine the equilibrium constant, K c, for the following chemical reaction: Fe 3+ (aq) + SCN (aq)
More informationChemical Equilibrium: Finding a Constant, Kc
Lab12 Chemical Equilibrium: Finding a Constant, Kc The purpose of this lab is to experimentally determine the equilibrium constant, K c, for the following chemical reaction: Fe 3+ (aq) + SCN (aq) FeSCN
More informationFinding the Constant K c 4/21/15 Maya Parks Partners: Ben Seufert, Caleb Shumpert. Abstract:
Finding the Constant K c 4/21/15 Maya Parks Partners: Ben Seufert, Caleb Shumpert Abstract: This lab was performed to find the chemical equilibrium constant K c for the reaction Fe 3+ + SCN FeSCN 2+ using
More informationThe Determination of an Equilibrium Constant
The Determination of an Equilibrium Constant Computer 10 Chemical reactions occur to reach a state of equilibrium. The equilibrium state can be characterized by quantitatively defining its equilibrium
More informationThe Determination of an Equilibrium Constant
The Determination of an Equilibrium Constant Calculator 10 Chemical reactions occur to reach a state of equilibrium. The equilibrium state can be characterized by quantitatively defining its equilibrium
More informationThe Determination of an Equilibrium Constant
The Determination of an Equilibrium Constant Chemistry 102 10 Chemical reactions occur to reach a state of equilibrium. The equilibrium state can be characterized by quantitatively defining its equilibrium
More information1iI1E. The Determination of 0 an Equilibrium Constant [LU. Computer
Computer The Determination of 0 an Equilibrium Constant Chemical reactions occur to reach a state of equilibrium. The equilibrium state can be characterized by quantitatively defining its equilibrium constant,
More informationLab 13.3 Determining K c via Colorimetry
BACKGROUND Most chemical reactions are reversible. They will proceed forward to a point where the products they have formed begin to collide with one another and reform the original reactants. When the
More informationThe Determination of an Equilibrium Constant
LabQuest 10 The equilibrium state of a chemical reaction can be characterized by quantitatively defining its equilibrium constant, Keq. In this experiment, you will determine the value of Keq for the reaction
More information2 (aq) [FeSCN [Fe 3JSCN] Figure 1
The Determination of an Equilibrium Constant Computer Chemical reactions occur to reach a state of equilibrium. The equilibrium state can be characterized by quantitatively defining its equilibrium constant,
More informationD E T E R M I N A T I O N O F K e q L A B
South Pasadena Honors Chemistry Name 8 Equilibrium Period Date D E T E R M I N A T I O N O F K e q L A B Lab Overview In a reversible reaction, equilibrium is the state at which the rates of forward and
More information9 Equilibrium. Aubrey High School PreAP -Chemistry. Name Period Date / /
Aubrey High School PreAP -Chemistry 9 Equilibrium Name Period Date / / 9.2 Determination of Keq Lab - Equilibrium Problems Lab Overview In a reversible reaction, equilibrium is the state at which the rates
More informationDetermining the Concentration of a Solution: Beer s Law. Evaluation copy. Figure 1
Determining the Concentration of a Solution: Beer s Law Computer 17 The primary objective of this experiment is to determine the concentration of an unknown copper (II) sulfate solution. You will use a
More informationDetermining the Concentration of a Solution: Beer s Law
Determining the Concentration of a Solution: Beer s Law LabQuest 11 The primary objective of this experiment is to determine the concentration of an unknown nickel (II) sulfate solution. You will be using
More informationDETERMINATION OF K c FOR AN EQUILIBRIUM SYSTEM
DETERMINATION OF K c FOR AN EQUILIBRIUM SYSTEM 1 Purpose: To determine the equilibrium constant K c for an equilibrium system using spectrophotometry to measure the concentration of a colored complex ion.
More informationLab #12: Determination of a Chemical Equilibrium Constant
Lab #12: Determination of a Chemical Equilibrium Constant Objectives: 1. Determine the equilibrium constant of the formation of the thiocyanatoiron (III) ions. 2. Understand the application of using a
More informationaa + bb cc + dd Equation 1
Experiment: The Determination of K eq for FeSCN 2+ Introduction For any reversible chemical reaction at equilibrium, the concentrations of all reactants and products are constant or stable. There is no
More informationK = [C]c [D] d [A] a [B] b (5)
Chem 1B Dr. White 19 Experiment 3: Determination of an Equilibrium Constant Objectives To determine the equilibrium constant for a reaction. Introduction Equilibrium is a dynamic state in which, at a given
More informationA = km (6) A = k [FeSCN 2+ ] KNOWN [FeSCN 2+ ] MEASURED A (Spec 20) CALCULATED k 3.0 x x x x 10-5 AVERAGE k =
Method I. Analysis by Spectrophotometric Measurement We ll be using the spectrophotometer ( Spec 20 ) to compare absorbances (A) indicated by the equipment and known concentrations of iron(iii) thiocyanate
More informationANSWERS: UNIT 3 EQUILIBRIUM I
ANSWERS: UNIT 3 EQUILIBRIUM I 1. a) [NaOH] = 4.00 g/40 g/mol / 0.10 L ii) [CaCl 2 ] = 16.0 g/111 g/mol / 0.250 L = 1.00 M = 0.577 M iii) [KOH] = 14.0 g/56 g/mol / 0.075 L iv) [H 2 C 2 O 4 ] = 6.75 g/90
More informationAP Chemistry Laboratory #16: Determination of the Equilibrium Constant of FeSCN 2+
AP Chemistry Laboratory #16: Determination of the Equilibrium Constant of FeSCN 2 Lab days: Thursday and Friday, February 22-23, 2018 Lab due: Tuesday, February 27, 2018 Goal (list in your lab book): The
More informationExperiment #7. Determination of an Equilibrium Constant
Experiment #7. Determination of an Equilibrium Constant Introduction It is frequently assumed that reactions go to completion, that all of the reactants are converted into products. Most chemical reactions
More informationDetermination of an Equilibrium Constant
7 Determination of an Equilibrium Constant Introduction When chemical substances react, the reaction typically does not go to completion. Rather, the system goes to some intermediate state in which the
More informationEXPERIMENT 5: PHOTOMETRIC DETERMINATION OF AN EQUILIBRIUM CONSTANT
EXPERIMENT 5: PHOTOMETRIC DETERMINATION OF AN EQUILIBRIUM CONSTANT The following preparatory questions should be answered before coming to class. They are intended to introduce you to several ideas important
More informationAspirin Lab By Maya Parks Partner: Ben Seufert 6/5/15, 6/8/15
Aspirin Lab By Maya Parks Partner: Ben Seufert 6/5/15, 6/8/15 Abstract: This lab was performed to synthesize acetyl salicylic acid or aspirin from a carboxylic acid and an alcohol. We had learned in class
More informationExperiment 12H, Parts A and B
Experiment 12H, Parts A and B AHRM 8/17 PRINCIPLES OF EQUILIBRIUM AND THERMODYNAMICS MATERIALS: PURPOSE: 0.0200 M Fe(NO 3 ) 3 in 1 M HNO 3, 0.000200 M KSCN, 2.0 M HNO 3, solid Fe(NO 3 ) 3. 9H 2 O with
More informationDetermination of an Equilibrium Constant Minneapolis Community and Technical College Principles of Chemistry II, C1152 v.1.16
Determination of an Equilibrium Constant Minneapolis Community and Technical College Principles of Chemistry II, C1152 v.1.16 I. Introduction Equilibrium Consider the following situation: It is rush hour
More informationAP* General Equilibrium Free Response Questions page 1
AP* General Equilibrium Free Response Questions page 1 General Equilibrium Problems 1983 Sulfuryl chloride, SO 2 Cl 2, is a highly reactive gaseous compound. When heated, it decomposes as follows: SO 2
More informationThe Synthesis and Analysis of Aspirin
The Synthesis and Analysis of Aspirin Computer 22 Aspirin, the ubiquitous pain reliever, goes by the chemical name acetylsalicylic acid. One of the compounds used in the synthesis of aspirin is salicylic
More informationDetermining the Concentration of a Solution: Beer s Law
Determining the Concentration of a Solution: Beer s Law The primary objective of this experiment is to determine the concentration of an unknown cobalt (II) chloride solution. You will use a Vernier SpectroVis
More informationTHE IRON(III) THIOCYANATE REACTION SYSTEM
Experiment 7 THE IRON(III) THIOCYANATE REACTION SYSTEM Prepared by Ross S. Nord, Chemistry Department, Eastern Michigan University PURPOSE To investigate a novel reaction system by utilizing a spectrophotometer.
More informationSpectrophotometric Determination of an Equilibrium Constant
Spectrophotometric Determination of an Equilibrium Constant v021214 Objective To determine the equilibrium constant (K c ) for the reaction of iron (III) ion with thiocyanate (SCN - ) to form the thiocyanatoiron(iii)
More informationExperiment 11 Beer s Law
Experiment 11 Beer s Law OUTCOMES After completing this experiment, the student should be able to: determine the wavelength (color) of maximum absorbance for a solution. examine the relationship between
More informationLab #16: Determination of the Equilibrium Name: Constant of FeSCN 2+ Lab Exercise. 10 points USE BLUE/BLACK INK!!!! Date: Hour:
Lab #16: Determination of the Equilibrium Name: Constant of FeSCN 2+ Lab Exercise Chemistry II Partner: 10 points USE BLUE/BLACK INK!!!! Date: Hour: Goal: The goal of this lab is to determine the equilibrium
More informationEXPERIMENT 6: Photometric Determination of an Equilibrium Constant
EXPERIMENT 6: Photometric Determination of an Equilibrium Constant The following preparatory questions should be answered before coming to class. They are intended to introduce you to several ideas important
More informationRate Law Determination of the Crystal Violet Reaction. Evaluation copy
Rate Law Determination of the Crystal Violet Reaction Computer 30 In this experiment, you will observe the reaction between crystal violet and sodium hydroxide. One objective is to study the relationship
More informationAP* General Equilibrium Free Response Questions page 1
AP* General Equilibrium Free Response Questions page 1 General Equilibrium Problems 1983 Sulfuryl chloride, SO 2 Cl 2, is a highly reactive gaseous compound. When heated, it decomposes as follows: SO 2
More informationa) Write the expression for the equilibrium constant, K eq
Chemistry 12 K eq Calculations Worksheet Name: Date: Block: 1. Given the equilibrium equation below: A 2(g) + B 2(g) 2AB (g) If, at equilibrium, the concentrations are as follows: [A 2] = 3.45 M, [B 2]
More informationExperiment 11 Beer s Law
Experiment 11 Beer s Law OUTCOMES After completing this experiment, the student should be able to: determine the wavelength (color) of maximum absorbance for a solution. examine the relationship between
More informationDETERMINATION OF AN EQUILIBRIUM CONSTANT
DETERMINATION OF AN EQUILIBRIUM CONSTANT In this experiment the equilibrium properties of the reaction between the iron(iii) ion and the thiocyanate ion will be studied. The relevant chemical equation
More informationRate law Determination of the Crystal Violet Reaction Using the Isolation Method
Rate law Determination of the Crystal Violet Reaction Using the Isolation Method Introduction A common challenge in chemical kinetics is to determine the rate law for a reaction with multiple reactants.
More information1-50 ml beaker stirring rod 1-10 ml beaker 0.10 M NaOH (1 ml) calibrated plastic dropper (1 ml) 50 ml dispensing burette (for Crystal Violet)
Exercise 2 Page 1 Illinois Central College CHEMISTRY 132 Name: Kinetics, Part II. Equipment Objectives. 1-50 ml beaker stirring rod 1-10 ml beaker 0.10 M NaOH (1 ml) calibrated plastic dropper (1 ml) 1.5x10-5
More informationThe Advanced Placement Examination in Chemistry. Part II - Free Response Questions & Answers 1970 to Equilibrium
The Advanced Placement Examination in Chemistry Part II - Free Response Questions & Answers 1970 to 005 Equilibrium Teachers may reproduce this publication, in whole or in part, in limited print quantities
More informationExperimental Procedure. Lab 406
Experimental Procedure Lab 406 Overview A large number of qualitative tests and observations are performed. The effects that concentration changes and temperature changes have on a system at equilibrium
More informationExperiment 6: Determination of the Equilibrium Constant for Iron Thiocyanate Complex
Experiment 6: Determination of the Equilibrium Constant for Iron Thiocyanate Complex The data for this lab will be taken as a class to get one data set for the entire class. I. Introduction A. The Spectrophotometer
More informationExperiment 2: The Beer-Lambert Law for Thiocyanatoiron (III)
Chem 1B Dr. White 11 Experiment 2: The Beer-Lambert Law for Thiocyanatoiron (III) Objectives To use spectroscopy to relate the absorbance of a colored solution to its concentration. To prepare a Beer s
More informationExperiment 2: The Beer-Lambert Law for Thiocyanatoiron (III)
Chem 1B Saddleback College Dr. White 1 Experiment 2: The Beer-Lambert Law for Thiocyanatoiron (III) Objectives To use spectroscopy to relate the absorbance of a colored solution to its concentration. To
More informationCalculations Involving the Equilibrium Constant K eq )
Calculations Involving the Equilibrium Constant K eq ) 1. Given the equilibrium equation below: A 2(g) + B 2(g) 2AB (g) If, at equilibrium, the concentrations are as follows: [A 2 ] = 3.45 M, [B 2 ] =
More informationDetermination of the Equilibrium Constant for the Iron (III) thiocynate Reaction
Lab 4. Determination of the Equilibrium Constant for the Iron (III) thiocynate Reaction Prelab Assignment Before coming to lab: After reading "Lab Notebook Policy and Format for Lab Reports" handout, complete
More informationExperiment 8: DETERMINATION OF AN EQUILIBRIUM CONSTANT
Experiment 8: DETERMINATION OF AN EQUILIBRIUM CONSTANT Purpose: The equilibrium constant for the formation of iron(iii) thiocyanate complex ion is to be determined. Introduction: In the previous week,
More informationDetermination of an Equilibrium Constant Minneapolis Community and Technical College Principles of Chemistry II, C1152 v.9.13
Determination of an Equilibrium Constant Minneapolis Community and Technical College Principles of Chemistry II, C1152 v.9.13 I. Introduction Equilibrium Consider the following situation: It is rush hour
More informationDetermining the Concentration of a Solution: Beer s Law
Determining the Concentration of a Solution: Beer s Law Vernier Spectrometer 1 The primary objective of this experiment is to determine the concentration of an unknown copper (II) sulfate solution. You
More informationAqueous Balance: Equilibrium
Activity 4 Aqueous Balance: Equilibrium GOALS In this activity you will: Determine ph and understand its meaning. Learn the basic principles behind equilibrium and the law of mass action. Calculate a solubility
More informationTHE TEMPERATURE DEPENDENCE OF THE EQUILIBRIUM CONSTANT
Experiment 7B THE TEMPERATURE DEPENDENCE OF THE EQUILIBRIUM CONSTANT Prepared by Ross S. Nord, Chemistry Department, Eastern Michigan University PURPOSE To investigate the relationship between the equilibrium
More information3 A (aq) + 2 D (aq) 4 C (g) + B (s) + 2 E (l)
AP Chemistry Test (Chapter 13) Multiple Choice (20%) 1) Which one best describes the K C for this reaction? 3 A (aq) + 2 D (aq) 4 C (g) + B (s) + 2 E (l) A) K c = [A] 3 [D] 2 B) K c = [C] 4 [B][E] 2 [C]
More informationEquilibrium and LeChatelier s Principle
1 Equilibrium and LeChatelier s Principle Purpose: To examine LeChatelier s Principle by studying disturbances applied to several equilibrium systems. Introduction Many chemical reactions reach a state
More informationLab 04 Equilibrium Constant of Ferric Thiocyanate
Lab 04 Equilibrium Constant of Ferric Thiocyanate Introduction This experiment will give you an opportunity to determine the equilibrium constant for the formation of Fe(SCN) 2+. The experiment will require
More informationCHEM Lab 7: Determination of an Equilibrium Constant using Spectroscopy
CHEM 0012 Lab 7: Determination of an Equilibrium Constant using Spectroscopy 1 Determination of the equilibrium constant of the following equilibrium system at room temperature. Fe 3+ (aq) + SCN- (aq)
More informationAP LAB 13a: Le Chatelier's Principle ADAPTED FROM VONDERBRINK: Lab Experiments for AP Chemistry
AP LAB 13a: Le Chatelier's Principle ADAPTED FROM VONDERBRINK: Lab Experiments for AP Chemistry Aim To investigate Le Chatelier's Principle Apparatus Test tubes, 100. ml beaker, stirring rod, test tube
More informationC H E M I S T R Y DETERMINATION OF AN EQUILIBRIUM CONSTANT
C H E M I S T R Y 1 5 0 Chemistry for Engineers DETERMINATION OF AN EQUILIBRIUM CONSTANT DEPARTMENT OF CHEMISTRY UNIVERSITY OF KANSAS Determination of an Equilibrium Constant Introduction A system is at
More informationc) Explain the observations in terms of the DYNAMIC NATURE of the equilibrium system.
Chemical Equilibrium - Part A: 1. At 25 o C and 101.3 kpa one mole of hydrogen gas and one mol of chlorine gas are reacted in a stoppered reaction vessel. After a certain time, three gases are detected
More informationCHEMISTRY 12 UNIT II EQUILIBRIUM D Learning Goals
CHEMISTRY 12 UNIT II EQUILIBRIUM D Learning Goals 1. Chemical equilibrium is said to by dynamic because a. The reaction proceeds quickly b. The mass of the reactants is decreasing c. The macroscopic properties
More information#11. Chemical Equilibrium
#11. Chemical Equilibrium Goal To observe and explain equilibrium shifts based on Le Chatelier s Principle. Introduction In any chemical reaction, reactants are converted to products. In some cases, some
More informationExp. 20: Spectrophotometric Analysis: Determination of the Equilibrium Constant for a Reaction
Exp. 20 - video (time: 41:13 minutes) Exp. 20: Spectrophotometric Analysis: Determination of the Equilibrium Constant for a Reaction Chemical Equilibrium Previously we have assumed that chemical reactions
More informationExperimental Procedure Lab 402
Experimental Procedure Lab 402 Overview One set of solutions having known molar concentrations of FeNCS 2+ is prepared for a calibration curve, a plot of absorbance versus concentration. A second set of
More informationQUESTIONS: Equilibria AS & AS
QUESTION (2012:2) Phosphorus pentachloride gas, PCl 5 (g), decomposes to form phosphorus trichloride gas, PCl 3 (g), and chlorine gas, Cl 2 (g). The equilibrium can be represented as: PCl 5 (g) Ý PCl 3
More informationExp 03 - Reaction Rate
GENERAL CHEMISTRY II CAÑADA COLLEGE SUMMER 2018 Exp 03 - Reaction Rate How the speed at which quantities change during a chemical reaction can be measured, predicted and used to understand the mechanism
More informationChemistry 112 SPECTROPHOTOMETRIC DETERMINATION OF AN EQUILIBRIUM CONSTANT
Chemistry 112 SPECTROPHOTOMETRIC DETERMINATION OF AN EQUILIBRIUM CONSTANT INTRODUCTION The principle underlying a spectrophotometric method of analysis involves the interaction of electromagnetic radiation
More information3 A (aq) + 2 D (aq) + 5 C (s) <==> 3 B (aq) + 4 E (aq) + 2 G (ppt)
AP Chemistry Test (Chapter 13) Multiple Choice (30%) 1) Which one best describes the K C for this reaction? 3 A (aq) + 2 D (aq) + 5 C (s) 3 B (aq) + 4 E (aq) + 2 G (ppt) A) K c = [A] 3 [D] 2 B) K
More informationHONORS LAB 11a: Le Chatelier's Principle ADAPTED FROM VONDERBRINK: Lab Experiments for AP Chemistry
HONORS LAB 11a: Le Chatelier's Principle ADAPTED FROM VONDERBRINK: Lab Experiments for AP Chemistry Aim To investigate Le Chatelier's Principle Apparatus Test tubes, 100. ml beaker, stirring rod, test
More informationAmend Lab 15 Observing Equilibrium
Amend Lab 15 Observing Equilibrium Page 57 Add 50 ml graduated cylinder Page 58 In Procedure: steps 1 & 2 change 4 ml to 2 ml step 4 change 60 ml dilution to 30 ml steps 6, 7, 8 change 0.5 g to ½ scoop
More informationExperimental Procedure Overview
Lab 4: Determination of an Equilibrium Constant using Spectroscopy Determination of the equilibrium constant of the following equilibrium system at room temperature. Fe 3+ (aq) + SCN (aq) Fe(SCN) 2+ (aq)
More informationof the ferric thiocyanate. This was done by creating the solutions and putting them into a
Introduction: The equation of the reaction is Fe 3+ (aq) + SCN - (aq) Fe(NCS) 2+ (aq). The objective of this lab was to determine the equilibrium constant (K) for the formation of the ferric thiocyanate.
More informationCHEMISTRY 135 General Chemistry II. Determination of an Equilibrium Constant
CHEMISTRY 135 General Chemistry II Determination of an Equilibrium Constant Show above is a laboratory sample from chemistry, not phlebotomy. [1] Is the bloody-looking product the main component of this
More informationDetermination of the Rate of a Reaction, Its Order, and Its Activation Energy
Determination of the Rate of a Reaction, Its Order, and Its Activation Energy Reaction kinetics is defined as the study of the rates of chemical reactions and their mechanisms. Reaction rate is simply
More informationExperiment 7: SIMULTANEOUS EQUILIBRIA
Experiment 7: SIMULTANEOUS EQUILIBRIA Purpose: A qualitative view of chemical equilibrium is explored based on the reaction of iron(iii) ion and thiocyanate ion to form the iron(iii) thiocyanate complex
More informationThe Effect of Alcohol on Biological Membranes
TEACHER INFORMATION The Effect of Alcohol on Biological Membranes Experiment 1. The student pages with complete instructions for using a Colorimeter or Spectrometer with LabQuest App and Logger Pro (computers)
More informationUnit 13 Kinetics & Equilibrium Page 1 of 14 Chemistry Kinetics, Entropy, Equilibrium, LeChatelier s Principle, K, Unit 13 Quiz: Unit 13 Test:
Unit 13 Kinetics & Equilibrium Page 1 of 14 Chemistry Kinetics, Entropy, Equilibrium, LeChatelier s Principle, K, Unit 13 Quiz: Unit 13 Test: Final Project: VOCABULARY: 1 Chemical equilibrium 2 equilibrium
More informationEXPERIMENT 9 ENTHALPY OF REACTION HESS S LAW
EXPERIMENT 9 ENTHALPY OF REACTION HESS S LAW INTRODUCTION Chemical changes are generally accompanied by energy changes; energy is absorbed or evolved, usually as heat. Breaking chemical bonds in reactants
More informationReview Unit #11. Review Unit # H 2 O (g) + CO (g) H 2(g) + CO 2(g) H>1
Review Unit #11 1. H 2 O (g) + CO (g) H 2(g) + CO 2(g) H>1 K c = 1.6 What effect would these changes have on the equilibrium position? a. Cool the mixture b. Increase the volume of the flask c. Add H 2(g)
More informationExperiment 18 - Absorption Spectroscopy and Beer s Law: Analysis of Cu 2+
Experiment 18 - Absorption Spectroscopy and Beer s Law: Analysis of Cu 2+ Many substances absorb light. When light is absorbed, electrons in the ground state are excited to higher energy levels. Colored
More informationPRELIMINARY ACTIVITY FOR
PRELIMINARY ACTIVITY FOR Beer s Law Investigations Guided Inquiry Version Experiment 11 The primary objective of this Preliminary Activity is to determine the concentration of an unknown copper (II) sulfate
More information3 Chemical Equilibrium
Aubrey High School AP Chemistry 3 Chemical Equilibrium Name Period Date / / 3.1 Problems Chemical Analysis 1. Write the equilibrium constant expressions for the following reactions. How are they related
More informationUNIT 4: Heterogeneous EQUILIBRIUM (Chap 17-pg 759)
UNIT 4: Heterogeneous EQUILIBRIUM (Chap 17-pg 759) 4:1. Review your understanding of the Solution Process by reading CHAPTER 12 in particular 12.1 4 on pages 521 534.Then answer the following given the
More informationEquilibrium Practice Problems page 1
Equilibrium Practice Problems page 1 1988 D NH 4 HS(s) NH 3 (g) + H 2 S(g) ΔHº = +93 kilojoules The equilibrium above is established by placing solid NH 4 HS in an evacuated container at 25ºC. At equilibrium,
More informationExperiment 7 Buffer Capacity & Buffer Preparation
Chem 1B Dr. White 57 Experiment 7 Buffer Capacity & Buffer Preparation Objectives To learn how to choose a suitable conjugate acid- base pair for making a buffer of a given ph To gain experience in using
More informationEquilibrium and Ionic Strength Effects
Equilibrium and Ionic Strength Effects Objectives You will determine the thermodynamic equilibrium constant for the reaction between iron(iii) ion and thiocyanate ion to form iron(iii)-thiocyanate. Fe
More informationCHM 152 updated May 2011 Lab 6: Experimentally Determining an Equilibrium Constant using Spectrophotometry
CHM 152 updated May 2011 Lab 6: Experimentally Determining an Equilibrium Constant using Spectrophotometry Introduction In this lab you will experimentally determine the equilibrium constant with respect
More informationK P VERSUS K C PROPERTIES OF THE EQUILIBRIUM CONSTANT
K P VERSUS K C 1. What are the units of K p and K c for each of the following? a) 2H 2 S(g) 2H 2 (g) + S 2 (g) b) 4NH 3 (g) + 3O 2 (g) 2N 2 (g) + 6H 2 O(g) 2. What are the units of K p and K c for each
More informationPhotosynthesis. LabQuest OBJECTIVES
Photosynthesis LabQuest 4B The process of photosynthesis involves the use of energy to convert carbon dioxide and water into sugar, oxygen, and other organic compounds. This process is often summarized
More informationSolubility of KHT and Common ion Effect
Solubility of KHT and Common ion Effect v010516 You are encouraged to carefully read the following sections in Tro (3 rd ed.) to prepare for this experiment: Sec 16.5, pp 783-788 (Solubility Equilibria
More informationUnit F FR Practice General Equilibrium (pg 1 of 26)
Unit F FR Practice General Equilibrium (pg 1 of 26) 1. Answer the following questions about glucose, C6H12O6, an important biochemical energy source. (a) Write the empirical formula of glucose. In many
More informationK sp = [Pb 2+ ][I ] 2 (1)
Chem 1B Saddleback College Dr. White 1 Experiment 11: Determination of K sp Objectives To determine the concentration of an unknown using a Beer- Lambert Plot. To determine the K sp for a relatively insoluble
More information(Lab 6) Extraction of Caffeine: ranking various teas and coffees by drug content
(Lab 6) Extraction of Caffeine: ranking various teas and coffees by drug content Introduction Caffeine is one of three legal, mind-altering drugs available in the U.S without a prescription. Two common
More informationAP Chemistry Laboratory #15: Reaction Rate of Crystal Violet and Sodium Hydroxide. Lab days: Thursday and Friday, February 1-2, 2018
AP Chemistry Laboratory #15: Reaction Rate of Crystal Violet and Sodium Hydroxide Lab days: Thursday and Friday, February 1-2, 2018 Lab due: TBD Goal (list in your lab book): The goal of this lab is to
More informationExploring Equilibria
Exploring Equilibria Name: Chem 112 This experiment explores a variety of equilibrium systems. A reference Table of Reactions is attached to aid in your explanations. In this qualitative lab, your observations,
More informationEffects of Changing Conditions on the Chemical Equilibrium (Self-study Module)
Effects of Changing Conditions on the Chemical Equilibrium (Self-study Module) How do chemical equilibria behave, when conditions like concentration, pressure or temperature change? This self-study module
More informationAdditivity of Heats of Reaction: Hess s Law
Additivity of Heats of Reaction: Hess s Law Experiment In this experiment, you will use a Styrofoam-cup calorimeter to measure the heat released by three reactions. One of the reactions is the same as
More information