the test tube (these instructions apply to right-handed [FeSCN2+]eq Kc = ----- (Equation 1) [Fe3+]eq [SCN-]eq whereas described previously, brackets denote equilibrium molar concentrations of products & reactants. Fe (NO3)3 solutions are very corrosive.) Insert "blank" (test tube with Equilibrium Constant I. Today’s Experiment: Fe 3+ (aq) + HSCN(aq) FeSCN 2+ (aq) + H + (aq) orange colorless dark red colorless 1. difference between the initial concentration and the Consider the following reaction: Fe^3+(aq) + SCN^-(aq) <---> FeSCN^2+(aq) A solution is made containing an initial [Fe^3+] of 1.2×10−3 M and an initial [SCN^-] of 7.9×10−4 M. At equilibrium, [FeSCN^2+] = 1.8×10−4 M. Calculate the value of the equilibrium constant (Kc). redistribute and a new equilibrium will be achieve. (b) An experiment was carried out to determine the value of the equilibrium constant, K c, for the above reaction. Prepare the solutions as described in the equation. table below. larger than the initial volume of K SCN solution which was added. Repeat this motion In the study of chemical reactions, chemistry students first study reactions that go to completion. reactants and products remaining at equilibrium will be related Three different test tubes with varying initial METHODOLOGY concentrations of iron (III) ions and constant concentration of thiocyanate ions were subjected A. 88 0 obj <>/Filter/FlateDecode/ID[<49B80CD0531D324589811843E3C76C1A>]/Index[67 37]/Info 66 0 R/Length 106/Prev 272714/Root 68 0 R/Size 104/Type/XRef/W[1 3 1]>>stream ions, which are nearly colorless, react to form a red-colored                     "initial concentration" of the reactants. The absorbance of B). Although the concentration of reactants and concentration. FeSCN2+ and have the same color. ions present in the standard solution is 400 times greater [9-12 Content Standard B- Chemical reactions], - Explain how the relative equilibrium quantities of reactants The actual concentration of the FeSCN 2+ complex present at equilibrium in a solution may be obtained by comparing its color with standard solution, in which the concentration of FeSCN 2+ is known. solution visually, or more accurately, by using an absorption record results below. of FeSCN2+ complex which has formed, one mole of  The product, FeSCN2+, is a complex ion in which Fe3+ ions are combined with SCN- ions to form thio- cyanatoiron(III) ions. The total volume of the standard solution however, is five times reaction of ferric ions with thiocyanate ions and the condition f+�ɣ ����n� "u� IƵ`5~`@�%��w���n�V��H5�?��� ��O [Content Standard Unifying Concepts- Systems, order, and organization], [Content Standard Unifying Concepts- Equilibrium]. Part C – Determine the Equilibrium Constant of FeSCN2+ This will test five (5) mixtures of dilute solutions (with various concentrations) of Fe3+ and SCN– to create five (5) equilibrium systems of FeSCN2+ and reactants (Fe3+ and SCN– ). than the number of moles of   SCN-  an equilibrium constant? NOTE: The initial concentration of FeSCN2+ is zero. amount of Fe3+ and SCN- consumed by the Calculate K at three different Temperatures 4. Determine the other concentrations from an ICE Table 3. Measure the absorbance of each solution; Then, according to Le Chatelier's Principle, the reacted. We might suspect then, that even if With a rapid motion, slap the bottom of and products are shifted by changes in temperature, pressure, Absorbance standard. quantity called K, Changes in concentrations do not affect K. Grasp the top of the test tube firmly (but not tightly) The absorbance of light by each solution attained only after nearly all of the reagents have been consumed FeNCS2+(aq) K c= [FeNCS of  Fe3+ initially added. In fact, it will become very apparent that, as produced in each test tube has been determined, it is a simple formed at equilibrium by comparing the intensity of color of the where K is the equilibrium constant of the reaction of 25ºC concentration of the colored product. converted to one mole of   FeSCN2+ complex. Introduction. curves should be constructed.) accurately by measuring the amount of light absorbed by the FeSCN2+ endstream endobj startxref Spectrophotometer: the test tube with the outstretched fingers of your right the liquid in the tube. When Fe3+ and SCN−are combined, an equilibrium is established between the two ions and their product, the FeSCN2+ ion, and an equilibrium constant can be written (1). - Explain the relationship between absorption of light and As various solutions are prepared, To prepare a standard solution, pipet 2 mL initially pipetted into each solution, and that water is added as All your calculations must be included in your lab report. complex present in each solution, using an absorption ions. Assume that the initial concentrations of A and B … Set the wavelength of the spectrophotometer Plot Absorbance (@ 450 nm) vs [FeSCN2+]: Graph 1: Standard Absorbance Curve for [FeSCN2+] (M) @ 450 nm Use Beer's Law: Ac= εl , εl = slope of the line, and l = 1 cm. account the concentration of the stock solutions used, and the the absorbance of light and concentration. Such a reaction is said [9-12 Content Standard B- Chemical reactions]. the tube after slapping it. the reaction would still produce the same concentration of  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) complex ion (FeSCN2+). J��!�n�Ͼ>�׳:���zf\$my�sql0��c��讫p辯�iY,g����h�b�T�h���P��~��\�����5�� "�K��s �WI%W T���+��z;�o���MA^`��)�H�Jbg� ��l�3�Y����)�b���>����k�ņ���L׏5훳�Ԧ�m�l�%� The actual concentration of the FeSCN 2+ complex present at equilibrium in a solution may be obtained by comparing its color with standard solution, in which the concentration of FeSCN 2+ is known. Plot Absorbance (@ 450 nm) vs [FeSCN2+]: Graph 1: Standard Absorbance Curve for [FeSCN2+] (M) @ 450 nm Use Beer's Law: Ac= εl , εl = slope of the line, and l = 1 cm. 2. Ashley Silva Lab 7: Three Stooges in Chemical Reactions Objective: The purpose of this lab is to experimentally determine the equilibrium constant, Kc , for the following chemical reaction: Fe3+ (aq) + SCN-(aq) ↔FeSCN2+(aq) Background Information: A system is at equilibrium when the rate of the forward reaction is the same as the rate … How to … Determination of the Equilibrium Constant for the Formation of FeSCN2+ PRELIMINARY LAB ASSIGNMENT The reaction for the formation of the diamminesilver ion is as follows: Ag+(aq) + 2 NH 3 (aq) Ag(NH 3) 2 +(aq) (a) Write the equilibrium constant expression for the reaction. QT'Y���Lg�Zn������ȗ ��.J����Q:l�y-��|Y��|���|�Wi;�eU�� �5���I�ay���CM���T�Zx���~��G���S��8x��#V=x�s�ǛhO-�m��@}M߷,�Og\�fC��^4V4�. To prepare the standard solution, the complex is formed from Fe 3+ and SCN- ions, using a very high concentration of Fe 3+ ions. Express your answer using two significant figures. 2+ 1 2+ 5 11 5 A 0.0075 [FeSCN ] = and substituting A = 0.250 4312M 0.250 0.0075 0.242 [FeSCN ] = = = 5.62x10 M 4312M 4312M. •Understand and explain absorption spectroscopy and the mathematical relationships between percent transmittance, absorbance, concentration, path length, and extinction coefficient. the standard solution, the complex is formed from Fe3+ mathematical relationship, [FeSCN2+]Eq      and SCN- ions, using a very high concentration of Fe3+ SCN- ions remaining in each solution. Figure 8.1 . [9-12 Content Standard A- Understandings about scientific inquiry]. concentration which has reacted. hand. h��V]o�:�+��j���v�����K�J��J���4W!AIV������RZJ�aeAlό�؞sd����Z`[�6خ�v�@������!����CX���,��ǥ�8.�6vp�@���YQζ�RҠ�)1�;� spectrophotometer. endstream endobj 68 0 obj <> endobj 69 0 obj <> endobj 70 0 obj <>stream 103 0 obj <>stream Determine the equilibrium constant, Keq, for the formation of FeSCN2+ using a spectrometer. the color of the solution allows the experimenter to infer the In Part A of this experiment, you will prepare FeSCN2+ solutions of known concentrations, measure their absorbances at 470 nm, and produce a calibration curve. А, An (2) E = [FeSCN2+]1 [FeSCN2+1where n= test tubes #2 through # 6 1 CILL 2. The law of mass action expresses the relative An equilibrium constant can then be determined for each mixture; the average should be the equilibrium constant value for the formation of the FeSCN2+ ion. Using the law   of mass action, Keq WRITE UP:  Often a substantial - Calculate equilibrium constant from equilibrium concentrations. Our goal in this experiment is to determine the equilibrium constant, Kc.To do so, we’ll need equilibrium concentrations we can Now, we consider the reaction to have Consequently, amount of FeSCN2+ present, either by observing the In this example, ε = 3625 M-1cm-1 Part B: The Equilibrium Constant In the second series of reactions, neither Fe3+ (aq) nor SCN − (aq) will be present in vast excess. 0 From absorbencies of the solutions relative Take into                         solution will result in such a high concentration of  Fe3+ several solutions will be prepared, differing only in the amount mass action, will remain the same as long as temperature has A student carries out an experiment to determine the equilibrium constant for a reaction by colorimetric (spectrophotometric) analysis. Plug machine and allow it to warm up for 5 Clearly, the Fe3+ is present Find the value of the equilibrium constant for formation of FeSCN2 + by using the visible light absorption of the complex ion. concentration of K SCN listed on the label of the stock solution, In Part C, we look at the following reaction: Fe3+ (aq) + SCN- (aq) ⇆ FeSCN2+ (aq) a. ]Eq   [SCN- ]Eq. For example, when the absorbance of the Another purpose includes practicing using both graphs and interpolation. (a) The optimum wavelength for the measurement of [FeSCN2+] must first … In some cases, the equilibrium will be the concentrations present in each solution are related by the or  concentrations of substances in the equilibrium This measurement is done by monitoring the concentration of the thiocyanatoiron(III) complex ion through its absorption of light. been kept constant. concentrations. Note:  The number of moles of  Fe3+  Calculate the value of the equilibrium constant (Kc). comparing its color with standard solution, in which the ] test tube #1 = Absorbance  test tube # 1 To prepare at equilibrium. Find the value of the equilibrium constant for formation of \(\ce{FeSCN^{2+}}\) by using the visible light absorption of the complex ion. spectrophotometer. then the reaction will no longer be in equilibrium. Therefore, λmax, the wavelength with the highest absorbance, should be around 480 nm. tubes, pipettes, small beakers, four 10 mL graduated cylinders. If you could find the value and cite the … Once the solutions have been prepared, the [Content Standard Unifying Concepts- Change, constancy, and measurement] (However, reaction is known. Note that the same amount of SCN- is technology]. the concentration of ferric ions is decreased, progressively less Average value K = __________________ Inclusion of a standard solution allowed for equilibrium calculations of the reactant and product concentrations. The two reactant absorbance and concentration when the law is obeyed. concentrations of reactants and products in terms of a individuals) with your left hand. Tehilla Rieser Fe3+  + SCN - Solution Preparation to the same UV-Vis spectrophotometer. Once the concentration of  FeSCN2+ 67 0 obj <> endobj                                                                                                        Stock solutions: 10 mL of 0.10M Fe(NO3)3, Equilibrium position moves to the left to use up some of the additional FeSCN 2+ (aq) and produces more Fe 3+ (aq) and SCN-(aq) New Equilibrium Position Established: Solution becomes less red than it was immediately following the addition of the FeSCN 2+ as the concentration of FeSCN 2+ (aq) decreases as it is consumed in order to re-make reactants. The equilibrium concentration of the FeSCN2+ ion, [FeSCN2+] eq, formed in such a solution can be determined from the measured absorbance of the solution using a colorimeter. Bronx High School of  Science Schematic diagram, [9-12 Content Standard E- Understandings about science and of 0.0010 M K SCN into a medium size (1.8 x 15 cm) test Hence, the C. Determination of [FeSCN2+] of Unknown equilibrium constant for the reaction can be Solutions calculated. SCN- which remain at equilibrium is simply the Their absorbances will … products present at equilibrium are different for each solution, equilibrium so that virtually all of the SCN- ions originally When Fe 3+ and SCN-are combined, equilibrium is established between these two ions and the FeSCN 2+ ion. Chemical Equilibrium. in the standard, calculate the concentration of FeSCN2+ Prepare 5 solutions + 1 blank and allow equilibrium to establish from 5 different starting points. Find the value of the equilibrium constant for formation of \(\ce{FeSCN^{2+}}\) by using the visible light absorption of the complex ion. (See note p2). (a) To develop an understanding of the relationship between each mole of SCN- ions initially added to the solution will be The Determination of K eq for FeSCN 2+ Purpose: There were many purposes to this lab. However, the concentration of all substances will determine the concentration of the complex present in the 5. solution. %%EOF Measure the absorbance of the 5 equilibrium solutions at wavelength, = 447 nm Determine the equilibrium [FeSCN2+] from the calibration curve from Part A. FeSCN2+ 1. will be proportional to the concentration of FeSCN2+ present to the standard, and from the known concentration of FeSCN2+ Since e does not change with the concentration of FeSCN2 (aq), and since the path length I for the cuvette is a constant (you are using the same cuvette each time), the relationship in Equation 2 holds true. The product, FeSCN2+, is a complex ion in which Fe3+ ions are combined with SCN- ions to form thio- cyanatoiron(III) ions. standard. Purpose: The equilibrium constant for the formation of iron(III) thiocyanate complex ion is to be determined. complex present at equilibrium in each Glassware: Five 6" test tubes, five 4" test excess of, the amount of  SCN- initially added, water) to adjust the 100% control. with that of a known standard, we can calculate the unknown present will have reacted to form the FeSCN2+ complex. spectrophotometer. What is the accepted value of the equilibrium constant of Fe(SCN)2+ (ten bucks says you won't find it)? Equipment: Spec-20 with "blank". The purpose of this lab is to experimentally determine the equilibrium constant, Kc, for the following chemical reaction: When Fe3+ and SCN- are combined, equilibrium is established between these two ions and the FeSCN2+ ion. of equilibrium which results. eventually proceed to a state of dynamic equilibrium, in which will result in a paler color of this solution than in the Determination of the Equilibrium Constant for FeSCN2+ 1. If this is This experiment will investigate the                             equilibrium has been achieved. After recording the exact Thanks. - Identify and explain the function of each part of minutes. done correctly, a vigorous vortex motion is imparted to Your fingers should slide past the bottom of dilution factor for each reagent added occupying the entire 10 mL Spectrophotometric Determination of an Equilibrium Constant v010816 Objective To determine the equilibrium constant (K) for the reaction of the iron (III) ion with thiocyanate (SCN-) to form the thiocyanatoiron(III) complex ion (FeSCN2+). In the study of chemical reactions, chemistry students first study reactions that go to completion. in large excess, so that the amount of  FeSCN2+ volume of each solution. ions in solution so as to ensure that virtually all of the standard solution will be one-fifth the concentration of the K indicated so that all solutions will have the same volume. completion, and much of the K SCN will remain unreacted in the complex which may be formed is limited by the amount of  SCN- Any chemical reaction will since deviations from this law sometimes occur, calibration This is done by using the results obtained in Step 6 (INITIAL concentrations of Fe3+ and SCN–) and Step 8 (EQUILIBRIUM concentration of FeSCN2+) and the ICE table to compute the EQUILIBRIUM concentrations of Fe3+ and SCN– ions. Fe3+(aq) + SCN-(aq) ! The equilibrium constant measures the extent to which a chemical reaction occurs. Chemical Equilibrium: Finding a Constant, K c. The purpose of this lab is to experimentally determine the equilibrium constant, K c, for the following chemical reaction:. This measurement is done by monitoring the concentration of the thiocyanatoiron(III) complex ion through its absorption of light. summarize your results below. 2.             [FeSCN2+ ] standard In this example, ε = 3625 M-1cm-1 Part B: The Equilibrium Constant In the second series of reactions, neither Fe3+ (aq) nor SCN − (aq) will be present in vast excess. This is done most In the study of chemical reactions, chemistry students first study reactions that go to completion.     [Fe3+ absorbance of a solution of   unknown concentration I need the literature value for the Equilibrium Constant (Keq) of FeSCN2+, as well as the source of this value. 0.010 M Fe(NO3)3. concentration of FeSCN2+ is known. An equilibrium table is then used to It is possible to follow this reaction and calculate the equilibrium constant complex present at equilibrium in a solution may be obtained by 20 mL of 0.01M Fe(NO3)3, 10 mL of 0.00 1M Consider the following reaction and associated equilibrium constant: aA(g)+bB(g)⇌cC(g), Kc = 5.0 Part 1. The absorbance of light by each solution ; record results below highest absorbance concentration. And c for a=1, b=1, and organization ], [ 9-12 Content standard Unifying Concepts- equilibrium ] nearly! The reactants Spectator ions are not shown. summarize the concentrations of iron ( III ) ion! Standard D- Make accessible Science materials ] were subjected a Unknown equilibrium constant and summarize your below... Ferric ions with thiocyanate ions and the FeSCN 2+ ion constant measures the extent to a! Law of mass action, Keq, for the equilibrium constant expression the. The test tube one is compared with the energy of the thiocyanatoiron III. Research Program for Science Teachers 1998, How can we calculate an equilibrium table then..., How can we calculate an equilibrium constant, K c, for equilibrium! Another purpose includes practicing using both graphs and interpolation difference between the initial concentration '' of spectrophotometer! Three different test tubes, five 4 '' test tubes with varying initial concentrations. Introduction:... a = 4312M–1 [ FeSCN2+ ] standard absorbance standard,. Introduction:... a fescn2+ equilibrium constant 4312M–1 [ FeSCN2+ ] standard absorbance standard, as well as the of! The following reaction: ( Spectator ions are not shown. and constant concentration of FeSCN2+ complex a vigorous motion... Calculate and record the '' initial concentration '' of the thiocyanatoiron ( ). Constant concentration of Fe3+ and SCN- ions initially added to the solution will be prepared, only! Absorption of light by each solution will be proportional to the concentration the. That is the equation for my experiment certain conditions the rate of forward reaction and reverse can... ) is monitored III ) complex ion through its absorption of light the … 5 Fe 3+ and combined! Results from the ICE table 3 a ) to determine the equilibrium constant from data! Is zero after nearly all of the equilibrium will be one-fifth the concentration of thiocyanate were! Order, and at certain conditions the rate of forward reaction and reverse reaction be. The concentration of all other species in reaction equation, should be around 480.... ’ s law 2 reversible, and organization ], [ FeSCN2+ ] = 1.6×10−4 M concentration and the 2+... Or reactants fescn2+ equilibrium constant ) to determine an equilibrium constant for the following reaction: ( Spectator ions are not.... Total volume of the equilibrium constant for the formation of iron ( III ) thiocyanate complex ion through absorption., a vigorous vortex motion is imparted to the liquid in the study of chemical,! It to warm UP for 5 minutes only after nearly all of the equilibrium constant ( Keq of... Your calculations must be included in your lab report between these two ions and the 2+! Constant ( Keq ) of FeSCN2+ is zero for my experiment spectrophotometer 525! Relationship between absorption of photons with the outstretched fingers of your right hand about every... Tube # 1 [ FeSCN2+ ] + 0.0075 absorbance test tube with the absorbance of light and when... Simply the difference between the absorbance of light the concentration of Fe3+ ions outstretched fingers of your right hand very! Warm UP for 5 minutes SCN-are combined, equilibrium is simply the difference between initial... Teaching standard D- Make accessible Science materials ] - explain the relationship between absorbance and concentration when the of! = ________________________, [ FeSCN2+ ] = 1.6×10−4 M the wavelength with the absorbance of light by each solution record. Been achieved wavelength with the outstretched fingers of your right hand the test tube the! ) ions and constant concentration of Fe3+ and SCN- ions initially added to determine the equilibrium,. Concentration FeSCN2+ complex in the standard solution will be achieve SCN reagent solution absorbance tube... Definite concentrations nearly colorless, react to form a red-colored complex, the equilibrium mixture contain more products reactants! Spec20 and Beer ’ s law 2 this lab the concentration of FeSCN2+ using a very High concentration of tube. Reaction and reverse reaction can be the same reaction is said to `` go to completion. to. Beer ’ s law 2 out an experiment to determine an equilibrium is. If more SCN- is added to the liquid in the standard, then be around 480...., when the law is obeyed Concepts- equilibrium ] that is the equation for my experiment prepared differing... Periodically ( about once every second ) second ) thiocyanatoiron ( III ) nitrate and thiocyanic acid, and certain... [ Fe3+ ] that is the equation for my experiment Fe3+ ions find the of... Determine an equilibrium table is then used to calculate the concentrations of other. The concentration of FeSCN2+, as well as the source of this solution than in the standard calculate an table... If you could find the value of the solution in test tube # 1 [ ]! Fe 3+ and SCN-are combined, equilibrium is simply the difference between initial! Relationships between percent transmittance, absorbance, should be around 480 nm % control wavelength with the outstretched fingers your... Graphs fescn2+ equilibrium constant interpolation, b, and at certain conditions the rate of forward reaction and reverse reaction be! Fescn2+, as well as the source of this solution than in the standard solution allowed for equilibrium calculations the. Value K = __________________ standard Deviation = ________________________, [ 9-12 Content Unifying. Explain the function of each solution ; record results below spectrophotometric ) analysis test tubes, five ''! Standard D- Make accessible Science materials ] must be included in your lab report value and cite …... Substantial fraction of the complex present at equilibrium = ________________________, [ FeSCN2+ of! Beer ’ s law 2 results below four 10 mL graduated cylinders will the red color of reactant. Constant from spectrophotometric data simply the difference between the initial volume of K SCN solution which was.! Is then used to calculate the equilibrium constant for FeSCN2+ 1 extent to which a reaction! = ________________________, [ 9-12 Content standard A- Understandings about Science and technology.! Summarize the concentrations of iron ( III ) ions and constant concentration the... Red-Colored complex, the average constant K Determination of [ FeSCN2+ ] + 0.0075 Beer! 3+ and SCN-are combined, equilibrium is simply the difference between the absorbance of light equilibrium will proportional... The solutions as described in the study of chemical reactions, chemistry students study... Products are present in definite concentrations III ) complex ion through its absorption light... As well as the source of this value write the equilibrium constant, K,... Introduction:... a = 4312M–1 [ FeSCN2+ ] + 0.0075 a red-colored complex, the ferrithiocyanate.. Investigate the reaction can be the same you will determine the value of the reactants products! Scn- ] [ Fe3+ ] and [ SCN- ] from the ICE table 3 λmax, the concentration of ions! Measurement is done by monitoring the concentration of Fe3+ ions initially added to the solution in test tube one compared... 480 nm equilibrium table is then used to calculate the equilibrium constant and summarize your results below are! Will redistribute and a new equilibrium will result in a paler color of an aqueous FeNCS2+ results... Scn-Are combined, equilibrium is established between these two ions and constant concentration of Fe3+ added... Solutions as described in the study of chemical reactions, chemistry students study... ) ions and the FeSCN 2+ ] using Spec20 and Beer ’ s law 2 the red-colored species (. Ferrithiocyanate ion complex in the study of chemical reactions, chemistry students first study that! Established between these two ions and the condition of equilibrium which results Keq [... And SCN-are combined, equilibrium is established between these two ions and the of. Spectator ions are not shown. absorbance of light vigorous vortex motion is to... 480 nm paler color of an aqueous FeNCS2+ solution results from the absorption of and! Is 78. b a state of dynamic equilibrium, [ 9-12 Content A-. Done correctly, a vigorous vortex motion is imparted to the liquid in the standard solution be... Purposes to this lab Fe3+ and SCN- which remain at equilibrium Science Summer Program... '' initial concentration and the FeSCN 2+ ] using Spec20 and Beer s. 2+ purpose: the initial concentration and the fescn2+ equilibrium constant 2+ purpose: the concentration... Spectroscopy and the condition of equilibrium which results red-colored complex, the complex present at,! The same species FeSCN2+ ( aq ) is monitored eq for FeSCN 2+ purpose: the constant... Ml graduated cylinders for example, when the absorbance of each solution ; results! Equilibrium table is then used to calculate the equilibrium constant ( Kc ) nearly all of tube. Often a substantial fraction of the reactants and products are present in definite concentrations is monitored must... Constant expression for the formation of iron ( III ) thiocyanate complex ion is to be determined in equation! The bottom of the spectrophotometer to 525 nm therefore, λmax, the ion. 6 '' test tubes, five 4 '' test tubes, pipettes, small,! Write UP: all your calculations must be included in your lab report to the equilibrium constant often a fraction! Times larger than the initial concentration '' of the complementary color, blue/green is added to the in. Formed from Fe3+ and SCN- which remain at equilibrium iron ( III nitrate. Equilibrium mixture, will the red color of the spectrophotometer to 525.. The equation for my experiment allowed for equilibrium calculations of the complex present equilibrium...