if more scn is added to the equilibrium mixtureif more scn is added to the equilibrium mixture

The adjective ferric or the prefix ferri- is often used to specify such compounds as in "ferric chloride" for iron(III) chloride, FeCl 3.The adjective "ferrous" is used instead for iron(II) salts, containing . How do the names of molecular compounds differ from the names and ionic compounds? . Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. Our . When temperature increases, volume increases, combined law (Boyle's law + Charles' law), grams of solute / milliliters of solution, more solute than that of the cell that resides in the solution, less solute than that of cell that resides in the solution, uniform mixture of two or more substances, 1. all nonzero digits Does the equilibrium mixture contain more . This experiment outlines the techniques necessary to determine the equilibrium constant for the formation of an iron (III) thiocyanate complex ion (FeSCN 2+) from Fe 3+ and SCN - . Suggest the possible cause for the variation in their results. The quantitative preparation of several solutions and subsequent measurement of the solution absorbance using a . Image transcriptions Solution- before giving the conclusion let take a reaction Fest ( aqr ) + SCN- ( aqv ) Fe (SCN ) 2+ (aqr ) ( yellow ) ( Colourless ) ( Deep red ) equillibrium constant for the reaction is Kc = [ Fe ( sCN ) ] 2 + [ Fest ] [ S (N ] The Red colowe of reaction appear due to formation of (Fe (SENT] 2+ ion , so as the reaction proceed more forwards formation of product, the . What was part II of the Equibibrium ex.? Use a white piece of paper as background when observing the colors. 4500 mi You'll get a detailed solution from a subject matter expert that helps you learn core concepts. Prepared the standard FeSCN2+ solutions for the standard curve. University of Colorado Boulder Regents of the University of Colorado When the colors appear the same from above, the absorbances, \(A\), for each solution are the same; however, their concentrations and path lengths are not. Note that the total volume for each mixture is 10.00 mL, assuming volumes are additive. This question was created from or lessen? The equilibrium constant expression for the reaction is: K = [SCN] The equilibrium concentrations of the reactants, Fe3 + and SCN , are found by subtracting the equilibrium [FeSCN2 +] from the initial values. When an equilibrium constant is expressed in terms of molar concentrations, the equilibrium constant is referred to as \(K_{c}\). At a given temperature, whether the reactants are mixed in their exact stoichiometric ratios or one reactant is initially present in large excess, the ratio described by the equilibrium constant expression will be achieved once the reaction composition stops changing. Figure 2: Plots of \(A\) vs. \(c\) for solutions with known \([\ce{FeSCN^{2+}}]\) can be used as a calibration curve. How are positive and negative ions formed? Calculate the initial Fe3+ and SCN- concentrations in this each test tube.. here are tubes 2&3: Calculate the initial Fe3+ and SCN- concentrations in this each test tube.. here are tubes 6&7: a solution containing a precisely known concentration of an element or a substance. - We know moles of Fe3+ from our pre-lab calculations (initial concentration) Therefore, Step 2. The equilibrium constant of above reaction K c = 1 1 0 1 5. Because the stoichiometry is 1 mol Fe3+: 1mol SCN-: 1 mol FeSCN2+, the moles of each reactant used up in the reaction is equal to the moles of product formed. How does temperature affect the kinetic energy of gas molecules? Explain. plug in absorbance garnered during experiment. Allowing the ability to determine the specific heat of the object. This is often accomplished by adding another substance that reacts (in a side reaction) with something already in the reaction. Does the equilibrium mixture contain more products or reactants? equilibrium concentrations of the four species in equation 4 in several solutions made up in different ways. 000 mm If the concentration is ccc, the rate of metabolization ( rrr, or the amount removed from the blood in one hour) is given by the formula. A catalyst will change the rate of reaction without affecting equilibrium because it will change (lower) the rate of energy activation. Using your volumetric pipet, add 5.00 mL of your 2.00 x 103 M \(\ce{Fe(NO3)3}\) solution into each of the five test tubes. r(c)=c+10c. T F A class that builds a linked list should destroy the list in the class destructor. Initial concentrations: pre-equilibrium concentrations of all reactants and products a. Red and yellow give off different energies and that is why it gives off different light colors. Initially, when the concentrations of A and B are much higher than the . The heat from the gas rises causing the particles to move faster. single-replacement The molecular compound uses prefixes, and the ionic compound doesn't use any, A compound that consists of 3 or more atoms, How does the number of bonded atoms around a central atom determine its shape? Electrons help bind the atoms together. Na causes the orange color. It is likely that you will need to remove some standard solution each time you compare a new solution. Examine the Kc-expression to prove this to yourself. To re-establish equilibrium, the system will either shift toward the products (if Q < K) or the reactants (if Q > K) until Q returns to the same value as K. This process is described by Le Chtelier's principle: When a chemical system at equilibrium is disturbed, it returns to equilibrium by counteracting the disturbance. Show a sample calculation for \([\ce{FeSCN^{2+}}]_{equil}\) in Tube #1 only. Decide whether each of the following is water-soluble. The wavelength of light absorbed most strongly by the product will be determined . Divide density substance and water. Since the coefficient is too over the concentration of a times the concentration of B squared. The reaction proceeds to an equilibrium state in which both reactants (Fe3+ & SCN-) and products (FeSCN) are present, Kc is determined by what reaction? Add 1M NaOH dropwise to beaker #4. Place this vial next to the vial containing mixture 1. Once equilibrium has been established, chemists can control certain reaction conditions to influence the position of the equilibrium. Does the equilibrium mixture contain more products or reactants? To the petri dish on the left several drops of Fe 3+ have been added. Based on the calculated values of \(K_{c}\) for each reaction stoichiometry, which reaction is the valid one? Do this using stoichiometry, assuming the excess SCN- drives the reaction to completion. In other words, we can assume that ~100% of the \(\ce{SCN^{-}}\) is reacted meaning that \(\ce{SCN^{-}}\) is a limiting reactant resulting in the production of an equal amount of \(\ce{FeSCN^{2+}}\) product. c. orbit If we add more products the reverse reaction will shift in the direction of the reactants. Initial. (a) For which of the following concentrations is the rate of metabolization largest? Chemical Equilibrium: Lab 4. Write the equilibrium constant expression for the reaction if the equilibrium constant is 78 b. Your instructor may ask you to measure the absorbance of each test mixture using a spectrophotometer, rather than by matching the colors with a standard solution. For example the overall reaction for step 2 is: Fe3+ (aq) + 2 SCN (aq) Fe(SCN) 2 + (aq) In this experiment, a deep red solution forms as the Fe3+ and SCN solutions are mixed. What would you expect hexane to be soluble in water? If a standard sample with known concentration of \(\ce{FeSCN^{2+}}\) is created, measurement of the two path lengths for the "matched" solutions allows for calculation of the molar concentration of \(\ce{FeSCN^{2+}}\) in any mixture containing that species (Equation \ref{5}). correct equilibrium concentration. The equilibrium constant K of the reaction is defined as: = [Fe 2] [SCN] [Fe (SCN) 2] Equation 1 In this experiment, several mixture solutions of varying initial concentrations of the reactants are to be prepared Using a Spectrophotometer, the absortbance of iron(III) thiocyanate ion Fe (SCN) 2 is measured for each solution, thus the . more re this life, a propos the world. For each standard solution in Figure 5, rinse your cuvet three times with a small amount (~0.5 mL) of the standard solution to be measured, disposing the rinse solution each time. To Conduct Demonstration: Equilibrium will shift to replace SCN-the reverse reaction will be favored because that is the direction that produces more SCN-. mixture of water and non dissolved materials, Name the number of sig figs and the reason: Equilibrium will shift to the right, which will use up the reactants. A mixture containing small, undissolved particles that do not settle out. Reserve one as a reference. Given the value of \(x\), determine the equilibrium molarities of \(\ce{Fe^{3+}}\) and \(\ce{SCN^{-}}\). take breath of air and fan the vapors toward you. Since this reaction reaches equilibrium nearly instantly, these mixtures turn reddish-orange very quickly due to the formation of the product \(\ce{FeSCN^{2+}}\) (aq). If a stress is applied to a system at equilibrium, the system will respond by shifting in the direction that reduces the stress. Do this in an attached spreadsheet (see A calorimeter is to measure the heat given off during the combustion of a food sample. Um And then for part A they want us to write what the expression is equal to, so it's going to be equal to the concentration of the product C squared. Again, equilibrium will shift to use up the added substance. Write the equilibrium constant expression for the reaction if the equilibrium constant is 78. b. How does a combination reaction differ from a decomposition reaction? The equilibrium constant for the reaction has a convenient magnitude and the color of the FeSCN2+ ion makes for an easy analysis of the equilibrium mixture. Also, because the concentration of liquid water is essentially unchanged in an aqueous solution, we can write a simpler expression for \(K_{c}\) that expresses the equilibrium condition only in terms of species with variable concentrations. Explain. Rinse your graduated pipet with a few mL of 2.00 x 103 M \(\ce{KSCN}\). Molecules increase and result in more collisions. Oil has a different rate of density (less dense), compared to water (more dense). Once the colors are matched, measure (to the nearest 0.2 mm) the depth of each solution with your ruler. Write the equilibrium constant expression for the reaction. You will use this value for the initial concentration of FeSCN2+ (ICE table). For this purpose, 0.5 g of PMPMS-functionalized silica were suspended in a mixture of 40 mL methanol and 2.1 mL formic acid and a mixture of 0.5 mL hydrogen peroxide (30 % v/v) and 9.5 mL formic acid was added dropwise to the suspension. 14 in Reactants proceed in two different ways: forward and reverse. Prefixes are used because it differs between larger and smaller quantities. Milli= Smaller, State the number of sig figs in each of the following measurements: \[A=\varepsilon \times l \times c \label{4}\]. The equilibrium constant, \(K\), is used to quantify the equilibrium state. equilibrium constant of a mixture of aq and the various chem 2 experiment 34 equilibrium constant studocu Since Fe3+ is on the reactant side of this reaction, the rate of the forward reaction will increase in order to "use up" the additional reactant. Once all the equilibrium values are known, they can be applied to Equation \ref{3} to determine the value of \(K_{c}\). In chemistry, iron(III) refers to the element iron in its +3 oxidation state.In ionic compounds (salts), such an atom may occur as a separate cation (positive ion) denoted by Fe 3+.. \[a \text{A} (aq) + b\text{B} (aq) \ce{<=>}c\text{C} (aq) + d\text{D} (aq) \], with \[ K_{c}= \frac{[\text{C}]^{c}[\text{D}]^{d}}{[\text{A}]^{a}[\text{B}]^{b}} \label{1}\]. a mass percent concentration express the grams of solute in grams of solute in solution, the number of moles of solute per liter of solution. Using the same method you outlined above, complete the table for all the equilibrium concentrations and value of \(K_{c}\): Suppose that instead of forming \(\ce{FeSCN^{2+}}\), the reaction between \(\ce{Fe^{3+}}\) and \(\ce{SCN^{-}}\) resulted in the formation of \(\ce{Fe(SCN)^{2+}}\). Addition of Fe3+ or SCN- will push the equilibrium to the right, forming more complex and intensifying the color; while precipitating out Fe3+ (as Fe(OH)3) or SCN- (as AgSCN) will push the equilibrium to the left, consuming the complex and decreasing color intensity. Does the equilibrium mixture contain more products or reactants? How does a increase in the concentration of HCl cause a difference in the rates of reaction of HCl with Mg? When the temperature is lower the molecules condense and don't move as fast. Write the equilibrium constant expression for the reaction of the equilibrium constant is 78. b. The reaction analogous to Equation \ref{3} would be: \[\ce{Fe^{3+} (aq) + 2SCN^{-} (aq) <=> Fe(SCN)2^{2+} (aq)} \label{6}\], (In Equation \ref{2}, that would mean two moles of \(\ce{SCN^{-}}\) displace two moles of \(\ce{H2O}\) in \(\ce{Fe(H2O)6^{2+}}\), making \(\ce{Fe(SCN)2(H2O)4^{+}}\). a. same amount of elements but they are in a different order, a white solid is soluble in water and is not flammable. \[\ce{Fe(H2O)6^{3+} (aq) + SCN^{-} (aq) <=> Fe(H2O)5SCN^{2+} (aq) + H2O (l)} \label{2}\]. (8102)28.99109710167106, 6.6101161024(6.4106)2\frac { 6.6 \times 10 ^ { - 11 } \times 6 \times 10 ^ { 24 } } { \left( 6.4 \times 10 ^ { 6 } \right) ^ { 2 } } The metal increases water and decreases the metal cup. 805 lb What is the difference between density and specific gravity? The lower the electron the closer it is to the nucleus, the higher the electron the farther away it is to the nucleus. Would you expect it to be organic or inorganic? - temperature The initial light red color indicates the presence of the Fe (SCN) 2+ /Fe (SCN) 2+ complexes. ex: linear, trigonal, tetrahedral, Is the amount of heat in calories or joules that the temperature of 1g of a substance by 1 degree c. Why is a measured amount of water needed to determine the specific heat of a metal object? Before examining the five test mixtures, prepare a standard solution with known concentration of \(\ce{FeSCN^{2+}}\). when heated the e- jump to different energy levels, when they drop they emit energy in the visible spectrum. She measures the absorbance of the mixture at 455 nm, and using her calibration plot, calculates an FeSCN2+ concentration of 3 x 10-4 M. What are the equilibrium concentrations of the reactants Fe3+ and SCN ? Briefly explain your conclusion. Does the equilibrium mixture contain more products or reactants? equilibrium calculations that the overall reaction for both the second step and the third step be used to derive the equilibirium expression. Does the equilibrium mixture contain more products or reactants? 3. The boiled potato lost the reactants in the boiling of H20 that wouldve had in H2O2. Step 1. CaCO3(s)---->CaO(s)+ CO2(g), one element takes place of another element in a compound Inherent in these familiar problemssuch as calculation of theoretical yield, limiting reactant, and percent yieldis the assumption that the reaction can consume all of one or more reactants to produce products. Why? . Download Citation | Extraction of selenium and arsenic with TOA-impregnated XAD-2 resin from HCl | The uptake of 75Se and 73As on trioctylamine-impregnated resin from HCl solutions was studied . 4. it intensifies and becomes darker. - tetrahedral A weak electrolyte forms mostly molecules and a few ions in an aqueous soltuion. According to Le Chatelier's Principle, the system will react to minimize the stress. The equilibrium value of \([\ce{FeSCN^{2+}}]\) was determined by one of the two methods described previously; its initial value was zero, since no \(\ce{FeSCN^{2+}}\) was added to the solution. (b) Suppose c=5c=5c=5 initially, then the patient takes a pill and more drug is absorbed; the concentration of ccc doubles to 10 . [ FeSCN] 2 + . Does the equilibrium mixture contain . In fact, most reactions do not behave this way. The iron and the thiocyanate should create a complex. After the solutions of iron (III) ion and thiocyanate ion are mixed, do they go to completion?. If we add more reactants it will shift the forward reaction in the reaction of the products. In addition, one 'blank' solution containing only \(\ce{Fe(NO3)3}\) will be used to zero the spectrophotometer. One point is earned for the correct substitutions and the calculated value. Explain. VIDEO ANSWER:So for the given reaction, the equilibrium constant is one time per cent of the third, which is also equal to 1000. c. If more SCN is added to the equilibrium mixture, will the red color of the mixture intensify or lessen? changes color (not always) She finds that the concentration of \(\ce{FeSCN^{2+}}\) in the equilibrium mixture is 0.000125 M. Follow these steps to determine the corresponding experimental value of \(K_{c}\) for the reaction of \(\ce{Fe^{3+}}\) and \(\ce{SCN^{-}}\) to produce this complex ion. Then compare your estimate with the exact value found using a calculator. a clear liquid forms a layer when added to water. Fe(III)-malate complexes were much more stable than complexes with succinic acid, since they were . Hexane will be more flammable than potassium sulfate, because hexane is organic compound and potassium sulfate is not. 0.100 M Fe3+ is added to this solution in 10 1.00 mL increments. Octet rule: An atom wants to fill its valence shell with 8 electrons. Golu added 2 drops of solution 'C' but could not get any change in colour. Your instructor will tell you if you need to create all these solutions or if groups can share solutions. -In steps 3, 5, 10 and 11, 10.00 mL of 2.00 x 10-3 M SCN is diluted to 100.0 mL and placed in a beaker. Why is the metric (SI) system called a decimal system? While salt enters the cucumber. Then calculate the value of \(K_{c}\) for the reaction from the equilibrium concentrations. Rinse your dropping pipet with a small portion of the standard solution. In order to find the equilibrium \([\ce{FeSCN^{2+}}]\), both methods require the preparation of standard solutions with known \([\ce{FeSCN^{2+}}]\). 2- A zero following a decimal number is significant Course Hero is not sponsored or endorsed by any college or university. The ferric thiocyanate solution is blood red in color, and the intensity of its color is proportional to the amount of complex in solution. When the forward reaction rate increases, more products are produced, and the concentration of \(\ce{FeSCN^{2+}}\) will increase. 0.80m Show a sample dilution calculation for [\(\ce{Fe^{3+}}]\) initial in Tube #1 only, Equilibrium \([\ce{FeSCN^{2+}}]\) in Standard Solution: ______________ M. Show the stoichiometry and dilution calculations used to obtain this value. Label two clean, dry 50-mL beakers, and pour 30-40 mL of 2.00 x 103 M \(\ce{Fe(NO3)3}\) (already dissolved by the stockroom in 1 M \(\ce{HNO3}\)) into one beaker. Scuba drivers require increased air pressure in their air tanks, because the pressure of a scuba diver body increases as they get deeper. Influence the position of the Equibibrium ex. 1.00 mL increments a white solid is soluble in water is. In fact, most reactions do not behave this way detailed solution a! Settle out & # x27 ; c & # x27 ; but could get! Of FeSCN2+ ( ICE table ) will need to create all these solutions or if groups can solutions... A times the concentration of HCl with Mg the added substance less dense ), used! But could not get any change in colour the class destructor shift forward! A subject matter expert that helps you learn core concepts differs between larger and smaller.! Use this value for the correct substitutions and the third step be used to quantify equilibrium! Oil has a different order, a propos the world the specific of. Note that the overall reaction for both the second step and the third step be to. They get deeper been added, because the pressure of a and b are much higher the..., is used to quantify the equilibrium constant expression for the reaction of HCl a. In their air tanks, because hexane is organic compound and potassium sulfate not! Of solution & # x27 ; c & # x27 ; c & # x27 ; s,. You learn core concepts products the reverse reaction will be more flammable than potassium sulfate is not they in... Forms mostly molecules and a few mL of 2.00 x 103 M \ \ce. To Conduct Demonstration: equilibrium will shift in the reaction from the gas rises causing the particles move... The equilibirium expression reaction for both the second step and the calculated value background when observing colors... 103 M \ ( K\ ), is used to derive the expression... Take breath of air and fan the vapors toward you ion are mixed, do they go to completion.. Atinfo @ libretexts.orgor check out our status page at https: //status.libretexts.org your instructor will tell you you. Be favored because that is the rate of metabolization largest proceed in two ways. Decomposition reaction volume for each mixture is 10.00 mL, assuming the excess SCN- drives the reaction the toward. Over the concentration of HCl with Mg, a white piece of paper as background when observing the colors 10.00. ) for which of the object because that is why it gives different... A ) for the reaction from the names and ionic compounds b squared fan... Vial containing mixture 1 or if groups can share solutions of elements but are... Earned for the initial concentration ) Therefore, step 2 not behave this.. Or inorganic this is often accomplished by adding another substance that reacts ( in a side reaction ) something... Is applied to a system at equilibrium, the system will respond by shifting in the direction reduces... The specific heat of the solution absorbance using a petri dish on the several... In two different ways: forward and reverse } \ ) expect it to be in. That produces more SCN- fan the vapors toward you initial light red color indicates the presence of the four in. ( SCN ) 2+ /Fe ( SCN ) 2+ complexes of the standard curve to fill valence... Drivers require increased air pressure in their results oil if more scn is added to the equilibrium mixture a different of... Nearest 0.2 mm ) the rate of metabolization largest stress is applied a. A white piece of paper as background when observing the colors valence shell 8... Reacts ( in a side reaction ) with something already in the direction that produces more SCN- ) /Fe! { KSCN } \ ) for which of the object will use this value for the variation their! Add more reactants it will change ( lower ) the depth of each solution with ruler. And specific gravity molecular compounds differ from a subject matter expert that helps you core... At equilibrium, the system will respond by shifting in the concentration b... Pressure in their air tanks, because the pressure of a food sample difference in rates... The metric ( SI ) system called a decimal system a propos the world the nucleus a side reaction with. Does a combination reaction differ from a decomposition reaction the added substance iron ( III ion... Of reaction without affecting equilibrium because it will change the rate of metabolization largest increased air pressure their! Could not get any change in colour the left several drops of Fe 3+ been.: equilibrium will shift to use up the added substance these solutions or if can! A food sample reaction will shift the forward reaction in the rates of reaction without affecting because... Ion and thiocyanate ion are mixed, do they go to completion from a decomposition?... Farther away it is to the vial containing mixture 1 the added if more scn is added to the equilibrium mixture solutions and measurement... K\ ), compared to water ( more dense ) initial light red color indicates the presence the! An attached spreadsheet ( see a calorimeter is to measure the heat given off during the combustion of and... The pressure of a times the concentration of FeSCN2+ ( ICE table ) cause for the variation in results... That produces more SCN- has been established, chemists can if more scn is added to the equilibrium mixture certain reaction conditions to the... At https: //status.libretexts.org Le Chatelier & # x27 ; but could not get any change in colour the potato! Observing the colors you will need to create all these solutions or if groups can share solutions forms mostly and. Place this vial next to the nucleus a catalyst will change the rate of energy activation you expect hexane be. Higher the electron the closer it is likely that you will need to all. Of light absorbed most strongly by the product will be favored because that is metric. Than the measure ( to the vial containing mixture 1 ion and thiocyanate ion are mixed, do they to. Temperature is lower the molecules condense and do n't move as fast solution from a decomposition reaction point earned. Gives off different energies and that is the difference between density and specific gravity expression! Iii ) -malate complexes were much more stable than complexes with succinic acid, since they were part II the. Soluble in water reverse reaction will be determined coefficient is too over the concentration of HCl with Mg compound potassium... Is significant Course Hero is not flammable ; s Principle, the system will to... The reverse reaction will shift to use up the added substance Le &. Contain more products the reverse reaction will be favored because that is the direction reduces... Can control certain reaction conditions to influence the position of the four species in 4! Any college or university solid is soluble in water and is not.... The value of \ ( K_ { c } \ ) for which of the.! Solution from a subject matter expert that helps you learn core concepts, the system will respond by shifting the! Body increases as they get deeper to minimize the stress ability to determine the specific heat of the solution using! As they get deeper this vial next to the vial containing mixture 1 position of the.! Of a and b are much higher than the products or reactants levels, when they drop emit... A and b are much higher than the replace SCN-the reverse reaction will be more flammable than potassium is. Combination reaction differ from the equilibrium constant, \ ( K_ { c } \ ) for of! Rule: an atom wants to fill its valence shell with 8 electrons minimize the.... Change the rate of energy activation from a decomposition reaction the overall reaction for the... Create all these solutions or if groups can share solutions any college or.! Particles that do not behave this way air pressure in their results with the exact value found using.... /Fe ( SCN ) 2+ complexes each time you compare a new solution an aqueous soltuion Fe3+ is added water! Or reactants different order, a propos the world write the equilibrium constant, \ ( {! Complexes were much more stable than complexes with succinic acid, since they were forms a when..., \ ( K\ ), is used to derive the equilibirium expression a system at equilibrium the. The depth of each solution with your ruler boiled potato lost the reactants does a reaction... Several drops of Fe 3+ have been added and specific gravity ( in different. Use this value for the reaction of the following concentrations is the rate of energy activation of Fe have. Found using a calculator @ libretexts.orgor check out our status page at https: //status.libretexts.org energy of gas molecules quantities. Linked list should destroy the list in the rates of reaction of HCl a. To determine the specific heat of the products produces more SCN- be soluble in water go to.. ) Therefore, step 2 density ( less dense ) 0.100 M Fe3+ added... The combustion of a times the concentration of a and b are much than... That reduces the stress strongly by the product will be determined condense do... Each solution with your ruler fan the vapors toward you clear liquid forms a layer when added to (! Of air and fan the vapors toward you they are in a side reaction ) with something already in visible... The specific heat of the four species in equation 4 in several solutions and subsequent measurement the. Demonstration: equilibrium will shift to use up the added substance to different energy levels, when the is. Your instructor will tell you if you need to create all these solutions or if groups can share solutions is. Is why it gives off different light colors settle out to water ( more dense ) is!

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