Homework Help is Here – Start Your Trial Now!
Science
Chemistry
METHOD Your goal is to determine the equilibrium constant for reaction (4). In order to determine Keq, experimentally, we must find the equilibrium molarities of each of the species [Fe]eq, [H₂SSA]eq, and [FeSSA]eq from solution mixtures that you will prepare as described below. The Hydrogen ion concentration [H]eq may be assumed to remain constant since its concentration is much higher than the other species present at equilibrium, and therefore is omitted from the Keq expression. In your lab notebook abstract, you should write out the equilibrium constant expression Keq for this reaction. The product FeSSA, absorbs visible light, while all other species present are essentially colorless. We can therefore determine the equilibrium molarity of the product species FeSSA by measuring its absorbance at an appropriate wavelength and using Beer's Law, as explained below. The equilibrium molarities of the other species will be determined by using a reaction table, as you have done in homework problems and in class. Beer's Law. Beer's law is an empirical law stating that the concentration C (in moles per liter) of a chemical species in solution is directly proportional to its absorbance A: A&C with the proportionality constant being a product of the pathlength and the molar absorptivity & (a measure of how strongly the solution absorbs light of a given wavelength) A-EIC For our experiments, I is fixed at 1.0 cm. Thus, a graph of the molarities vs. the absorbances of various solutions (at a fixed appropriate wavelength) will yield a straight Ay line, the slope of which may be determined either manually (by calculating from Ax measured x and y values) or using a computer program such as Excel TM. Once the slope is known, molarities of unknown solutions may be calculated from their measured absorbance values. You should be familiar with this method, as it was employed in chem. 1A.

METHOD Your goal is to determine the equilibrium constant for reaction (4). In order to determine Keq, experimentally, we must find the equilibrium molarities of each of the species [Fe]eq, [H₂SSA]eq, and [FeSSA]eq from solution mixtures that you will prepare as described below. The Hydrogen ion concentration [H]eq may be assumed to remain constant since its concentration is much higher than the other species present at equilibrium, and therefore is omitted from the Keq expression. In your lab notebook abstract, you should write out the equilibrium constant expression Keq for this reaction. The product FeSSA, absorbs visible light, while all other species present are essentially colorless. We can therefore determine the equilibrium molarity of the product species FeSSA by measuring its absorbance at an appropriate wavelength and using Beer's Law, as explained below. The equilibrium molarities of the other species will be determined by using a reaction table, as you have done in homework problems and in class. Beer's Law. Beer's law is an empirical law stating that the concentration C (in moles per liter) of a chemical species in solution is directly proportional to its absorbance A: A&C with the proportionality constant being a product of the pathlength and the molar absorptivity & (a measure of how strongly the solution absorbs light of a given wavelength) A-EIC For our experiments, I is fixed at 1.0 cm. Thus, a graph of the molarities vs. the absorbances of various solutions (at a fixed appropriate wavelength) will yield a straight Ay line, the slope of which may be determined either manually (by calculating from Ax measured x and y values) or using a computer program such as Excel TM. Once the slope is known, molarities of unknown solutions may be calculated from their measured absorbance values. You should be familiar with this method, as it was employed in chem. 1A.

Chemistry
Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
See similar textbooks
icon
Related questions
Question
With the images attached please write 1 paragraph 1 paragraph: complete condense method describe Please please please answer everything it's very important please answer super super fast NOTE: This does not require hands-on experimentation
METHOD Your goal is to determine the equilibrium constant for reaction (4). In order to determine Keq, experimentally, we must find the equilibrium molarities of each of the species [Fe³+]eq, [H₂SSA]eq, and [FeSSA]eq from solution mixtures that you will prepare as described below. The Hydrogen ion concentration [H]eq may be assumed to remain constant since its concentration is much higher than the other species present at equilibrium, and therefore is omitted from the Keq expression. In your lab notebook abstract, you should write out the equilibrium constant expression Keq for this reaction. The product FeSSA, absorbs visible light, while all other species present are essentially colorless. We can therefore determine the equilibrium molarity of the product species FeSSA by measuring its absorbance at an appropriate wavelength and using Beer's Law, as explained below. The equilibrium molarities of the other species will be determined by using a reaction table, as you have done in homework problems and in class. Beer's Law. Beer's law is an empirical law stating that the concentration C (in moles per liter) of a chemical species in solution is directly proportional to its absorbance A: AxC with the proportionality constant being a product of the pathlength and the molar absorptivity & (a measure of how strongly the solution absorbs light of a given wavelength) A - EIC Ax For our experiments, I is fixed at 1.0 cm. Thus, a graph of the molarities vs. the absorbances of various solutions (at a fixed appropriate wavelength) will yield a straight line, the slope of which may be determined either manually (by calculating from measured x and y values) or using a computer program such as Excel TM. Once the slope is known, molarities of unknown solutions may be calculated from their measured absorbance values. You should be familiar with this method, as it was employed in chem. 1A.
Transcribed Image Text:METHOD Your goal is to determine the equilibrium constant for reaction (4). In order to determine Keq, experimentally, we must find the equilibrium molarities of each of the species [Fe³+]eq, [H₂SSA]eq, and [FeSSA]eq from solution mixtures that you will prepare as described below. The Hydrogen ion concentration [H]eq may be assumed to remain constant since its concentration is much higher than the other species present at equilibrium, and therefore is omitted from the Keq expression. In your lab notebook abstract, you should write out the equilibrium constant expression Keq for this reaction. The product FeSSA, absorbs visible light, while all other species present are essentially colorless. We can therefore determine the equilibrium molarity of the product species FeSSA by measuring its absorbance at an appropriate wavelength and using Beer's Law, as explained below. The equilibrium molarities of the other species will be determined by using a reaction table, as you have done in homework problems and in class. Beer's Law. Beer's law is an empirical law stating that the concentration C (in moles per liter) of a chemical species in solution is directly proportional to its absorbance A: AxC with the proportionality constant being a product of the pathlength and the molar absorptivity & (a measure of how strongly the solution absorbs light of a given wavelength) A - EIC Ax For our experiments, I is fixed at 1.0 cm. Thus, a graph of the molarities vs. the absorbances of various solutions (at a fixed appropriate wavelength) will yield a straight line, the slope of which may be determined either manually (by calculating from measured x and y values) or using a computer program such as Excel TM. Once the slope is known, molarities of unknown solutions may be calculated from their measured absorbance values. You should be familiar with this method, as it was employed in chem. 1A.
OBJECTIVES (1.) To gain experience with the important method of visible spectrophotometry; and (2.) use this technique to determine the equilibrium constant for the formation of the complex FeSSA(aq) from Fe³+ (aq) and H₂SSA ¹aq). THEORY EXPERIMENT 4 DETERMINATION OF AN EQUILIBRIUM CONSTANT BY SPECTROPHOTOMETRY All chemical reactions move spontaneously towards an equilibrium state when the reactants are mixed in arbitrary concentrations. The equilibrium state for a given temperature and pressure is reached when the concentrations of reactants and products are no longer changing. However, when the system approaches and then attains the equilibrium state, there are two opposite processes taking place: the reactant molecules are reacting to form products, and the product molecules are reacting in the reverse direction to form reactant molecules. At the final equilibrium state, the forward and reverse reactions are taking place at the same rate, so that there is no net change in the concentrations of the products and reactants. Mathematically, when the system reaches equilibrium, the product of the molarities of the products raised to their stoichiometric coefficients divided by the product of the molarities of the reactants raised to their stoichiometric coefficients is equal to a constant, called the equilibrium constant, Keq, As a general example, consider the reaction: aA(aq) + bB(aq) cC(aq) + dD(aq) where A (aq) and B(aq) are reactants, C(aq) and D(aq) are product species, and a,b,c, and d are their respective stoichiometric coefficients in the balanced equation. Away from equilibrium, the reaction quotient Q is defined as: [C] [D] [A] [B]* K = where the brackets represent the molarity of a species. As the system approaches equilibrium, Q→Keq, and at equilibrium Q=Keq, (1) ¸ [C]r₂^[D]c₂ª [A] [B] (2) where the subscripts eq signify the final equilibrium molarities of each species. Keq has a fixed value for any given temperature and pressure, but is independent of the molarity of the species present at equilibrium. 6
Transcribed Image Text:OBJECTIVES (1.) To gain experience with the important method of visible spectrophotometry; and (2.) use this technique to determine the equilibrium constant for the formation of the complex FeSSA(aq) from Fe³+ (aq) and H₂SSA ¹aq). THEORY EXPERIMENT 4 DETERMINATION OF AN EQUILIBRIUM CONSTANT BY SPECTROPHOTOMETRY All chemical reactions move spontaneously towards an equilibrium state when the reactants are mixed in arbitrary concentrations. The equilibrium state for a given temperature and pressure is reached when the concentrations of reactants and products are no longer changing. However, when the system approaches and then attains the equilibrium state, there are two opposite processes taking place: the reactant molecules are reacting to form products, and the product molecules are reacting in the reverse direction to form reactant molecules. At the final equilibrium state, the forward and reverse reactions are taking place at the same rate, so that there is no net change in the concentrations of the products and reactants. Mathematically, when the system reaches equilibrium, the product of the molarities of the products raised to their stoichiometric coefficients divided by the product of the molarities of the reactants raised to their stoichiometric coefficients is equal to a constant, called the equilibrium constant, Keq, As a general example, consider the reaction: aA(aq) + bB(aq) cC(aq) + dD(aq) where A (aq) and B(aq) are reactants, C(aq) and D(aq) are product species, and a,b,c, and d are their respective stoichiometric coefficients in the balanced equation. Away from equilibrium, the reaction quotient Q is defined as: [C] [D] [A] [B]* K = where the brackets represent the molarity of a species. As the system approaches equilibrium, Q→Keq, and at equilibrium Q=Keq, (1) ¸ [C]r₂^[D]c₂ª [A] [B] (2) where the subscripts eq signify the final equilibrium molarities of each species. Keq has a fixed value for any given temperature and pressure, but is independent of the molarity of the species present at equilibrium. 6
Expert Solution
steps

Step by step

Solved in 5 steps with 16 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Chemical Equilibrium
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
Chemistry
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY
SEE MORE TEXTBOOKS