An acid-base indicator, HIn, dissociates according to the following reaction in an aqueous solution. K. HIn(aq) = In (aq) + H* (aq) The protonated form of the indicator, HIn, has a molar absorptivity of 2777 M-1.cm-1 and the deprotonated form, In-, has a molar absorptivity of 19024 M-1.cm-1 at 440 nm. The pH of a solution containing a mixture of Hln and In- is adjusted to 5.86. The total concentration of HIn and In- is 0.000184 M. The absorbance of this solution was measured at 440 nm in a 1.00 cm cuvette and was determined to be 0.884. Calculate pka for HIn.

An acid-base indicator, HIn, dissociates according to the following reaction in an aqueous solution. K. HIn(aq) = In (aq) + H* (aq) The protonated form of the indicator, HIn, has a molar absorptivity of 2777 M-1.cm-1 and the deprotonated form, In-, has a molar absorptivity of 19024 M-1.cm-1 at 440 nm. The pH of a solution containing a mixture of Hln and In- is adjusted to 5.86. The total concentration of HIn and In- is 0.000184 M. The absorbance of this solution was measured at 440 nm in a 1.00 cm cuvette and was determined to be 0.884. Calculate pka for HIn.

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

Similar questions

Q1) in titration of the solution containing 0.1 Molar of I and 0.1 Molar of Cro,", with the solution of 0.1 mołar of Ag+, what is the titration error in first step? if the end point of first titration will be taken on the precipitation of Ag.Cro, KSP(Ag,Cro,)=101n KSP(Agi) = 10 Q2) Q2) How much mole of NH, to be added to 500 ml of the solution with pH-8.9 to dissolve 5x10 * of ABSCN? PKSP(AGSCN)=12 , PKa(NH.") =9.2, PKdAg(NH,)*/Ag+=7.2
A phosphate buffer contains KH2PO4 and K2HPO4. What is the net ionic equation for the buffering reaction that occurs when some HCl is added to the buffer solution? (A) H2PO4–(aq) + Cl–(aq) --> HPO42–(aq) + HCl(aq); (B) H2PO4–(aq) + H3O+(aq) --> H3PO4(aq) + H2O(aq); (C) HPO42–(aq) + Cl–(aq) --> PO43–(aq) + HCl(aq); (D) HPO42–(aq) + H3O+(aq) --> H2PO4–(aq) + H2O(aq);
A solution of malonic acid, H2C3H2O4H2C3H2O4 , was standardized by titration with 0.1000 M NaOHNaOH solution. If 21.68 mLmL of the NaOHNaOH solution were required to neutralize completely 13.00 mLmL of the malonic acid solution, what is the molarity of the malonic acid solution? H2C3H2O4+2NaOH→Na2C3H2O4+2H2OH2C3H2O4+2NaOH→Na2C3H2O4+2H2O
Q2 a M
What would be the equation for equilibrium constant for the following reaction? 4 Pb(OH)4 (aq) + 2H₂SO4 (aq) = Pb(SO4)2 (aq) + 4H₂O (1) OK= PM(OH), H₂SO0,] [P(SO), H₂O] 74 0 PHOH), H₂SO [Pb(SQ),] PL(SO), H₂O Pb(OH) [H₂SO4)² Pb(SO₂),,O [PHOH), H, SO₂] OK = OK (= O None of the above
Methyl orange is an indicator used for detecting the pH of acidic solutions. The red, protonated form of the indicator (HIn) dissociates into a yellow, deprotonated form (In¯) as shown in the reaction. The pKa for methyl orange is 3.4. HIn(aq) = H*(aq) + In¯(aq) yellow red Identify the color of a solution containing methyl orange Identify the color of a solution containing methyl orange indicator at pH 2. indicator at pH 3.4. orange yellow yellow orange red red Identify the color of a solution containing methyl orange indicator at pH 6. orange yellow red
Q1) In titration of the solution containing 0.1 Molar of I'and 0.1 Molar of Cro,", with the solution of 0.1 molar of Ag+ , what is the titration error in first step? if the end point of first titration will be taken on the precipitation of Ag.Cro. KSP(Ag.Cro.)=10112 KSP(Agl) = 10.1
What is the molar solubility of a hypothetical compound AB in a solution containing 0.15 M B- given a Ksp = 6 x 10-2? AB(s) = A*(aq) + B'(aq)
HA, a weak acid, also forms the ion HA, in solution. The reaction is HA(aq) + A (aq) = HA, (aq) The weak acid has K, = 8.64 × 10-7 and the reaction has K = 3.80. Calculate the concentrations of A, H*, and HA, in a 1.00 M solution of HA. [A¯] = M [H*] = M [HA,] = M
Moles SCN- used in titration (mol)Moles of Agt in 20.0 mL titrated (mol) [Ag*lequil (M)X= [Ag*Jinit - [Ag*lequil = Change (M) solve for flask d e and f
In some natural systems the pH must be maintained within very narrow limits. e.g. in human blood the pH must remain close to 7.4 or cell deterioration occurs. Blood contains several weak acid/conjugate base equilibria called buffers, which control the pH.One weak acid present in blood is the dihydrogen phosphate ion, H2PO4-(aq), for which the equilibrium in aqueous solution is H2PO4-(aq) +H2O(l) <--> HPO42-(aq) + H3O+(aq). a) What would be the effect on this equillibrium of adding hydrochloric acid solution?b) Write the expression for the equilibrium constant of this reaction.c) If 0.5 mol H2PO4- and 0.5 mol HPO42- are in equilibrium in 1.0L of aqueous solution, calculate the pH of the solution. (Ka for H2PO4-= 6.4 x 10-8)d) 0.010 mol HCl is now added to the 1.0L of the solution in c). Assuming that all the added H+ ions are used up in the equilibrium shift, calculate the concentrations of H2PO4- and HPO42-. Hence calcuate the pH of this solution.e) 0.010 mol HCl has been added…
The pK, values for the dibasic base B are pKi = 2.10 and pk2 = 7.49. %3! Calculate the pH at each of the points in the titration of 50.0 ml. of a 0.55 M B(aq) solution with 0.55 M HCI(aq). What is the pH before addition of any HCI? pH What is the pH after addition of 25.0 ml. HCI? pH = What is the pH after addition of 50.0 mL HC? pH What is the pH after addition of 75.0 mlL HCI? pH = What is the pH after addition of 100.0 ml. HCI? pH =