0.8 0.7- 0.6- 0.5- 0.4 0.3 0.2 0.1- 0 4 5 6 C. (ii) only D. (i) and (ii) 7 8 pH ● Free 9 Bound 10 11 ii. The free indicator is a stronger acid than the bound indicator. A. (i) only B. Neither (i) nor (ii) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 A scientist measured the absorbance of a pH indicator dye when it was free or bound to a small peptide at their respective maximum absorbance wavelengths. Which of the following options is CORRECT? i. The pka of the indicator increased upon peptide binding. 0

0.8 0.7- 0.6- 0.5- 0.4 0.3 0.2 0.1- 0 4 5 6 C. (ii) only D. (i) and (ii) 7 8 pH ● Free 9 Bound 10 11 ii. The free indicator is a stronger acid than the bound indicator. A. (i) only B. Neither (i) nor (ii) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 A scientist measured the absorbance of a pH indicator dye when it was free or bound to a small peptide at their respective maximum absorbance wavelengths. Which of the following options is CORRECT? i. The pka of the indicator increased upon peptide binding. 0

Chemistry: Principles and Practice

3rd Edition

ISBN:9780534420123

Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer

Publisher:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer

Chapter16: Reactions Between Acids And Bases

Section: Chapter Questions

Problem 16.85QE

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Similar questions

Consider an indicator that ionized as shown below for which its Ka = 1.0 x 10-4. HIn + H2O → H3O+ + In-yellow red Which of the responses contains all the true statements and no others? (1) The predominant color in its acid range is yellow.(2) In the middle of the pH range of its color change, a solution containing the indicator will probably be orange.(3) At pH = 7.00, a solution containing this indicator (and no other colored species) will be red. (Hint: Write the equilibrium constant expression for the indicator.)(4) At pH = 7.00, most of the indicator is in the un-ionized form.(5) The pH at which the indicator changes color is pH = 4.
Phenolphthalein indicator is a weak acid with Ka = 10-9 mol/dm-3. It is colourless while its conjugate base is pink in solution. Calculate the ratio of the number of pink particles to the number of colourless particles of this indicator in a solution of pH = 9
It is necessary to prepare 0.100 liters of buffer pH 4.70 with a concentration of 0.250 M, from a solution of acetic acid at 55.0% m/m (density = 1.010 g/mL) and sodium acetate of purity 97.0 %, how many g of salt do I need? (Ka = 1.78 x 10-5) (Note significant figures).
1. The reaction of ??? with ???3 is presented by the unbalanced chemical reaction below: ___ KOH(aq)+ ___ HNO3 (aq) ---> ___ KNO3 (aq)+ ___ H2O(l)Calculate the molar concentration of Nitric acid (???3) when 40.5−?? of 0.674 ? ???is required to quench 101.0?? of Nitric acid over phenolphthalein indicator.
An acid-base indicator is usually a weak acid with a characteristic color in the protonated and deprotonated forms. Because bromocresol green is an acid, it is convenient to represent its rather complex formula as HBCG. HBCG ionizes in water according to the following equation: HBCG + H2O ⇌ BCG- + H3O+ (yellow) (blue) a. Write the Ka expression for bromocresol green based on the equation above. b. When [BCG-] = [HBCG], then show that the expression simplifies to Ka = [H3O+]. If you know the pH of the solution, then the [H3O+] and Ka can be determined. c. What would be the color of the solution if there were equal concentrations of HBCG and BCG-?
1. Sketch the labelled pH curve for a reaction between 10.0 mL of 1.00 mol/L strong base with 1.00mol/L strong acid. Ensure that your sketch has a title and properly labeled axis. 2. During a titration with an acidic titrant, the endpoint is found to occur at a pH of 5.5. Choose anappropriate indicator and predict the colour change.
This is the reaction with Acid-Base indicator. Please explain clearly what the result below means. INDICATORS COLOR BLUE LITMUS PAPER TURNS RED RED LITMUS PAPER REMAINS RED CONGO RED RED/PINK PHENOLPHTHALEIN NO CHANGE
How to distinguish between an Acidic Buffer and Acidic Solution as well as Basic Buffer and Basic Solution? Is it based on the color exhibited sol. w/ indicator or pH level of a solution? Ex. Solution 1: 30.0 mL 0.10 M CH3COOH Solution 2: 15.0 mL 0.20 M CH3COOH – 15.0 mL 0.20 M NaCH3COO Both used methyl orange as indicator Solution Observed Color & Estimated pH range Classification (acidic/basic & buffer/solution) 1 a 1.0 M HCl Red pH < 3.1 (2.01pH) b 1.0 M NaOH Orange 3.1 < pH < 4.5 (3.98pH) c Control Red pH < 3.1 (2.91pH) 2 a 1.0 M HCl Yellow pH > 4.5 (4.73) b 1.0 M NaOH Yellow pH > 4.5 (4.82) c Control Yellow pH > 4.5 (4.76)
For the analysis of a 50 mL sample consisting of carbonate mixtures, when the phenolphthalein indicator is added and titrated with 0.1 M HCl, 10 ml of acid is consumed until the turning point. Since the bromocresol indicator is added after the first turning point and 15 mL of HCl acid is added, find the number of moles in the initial solution..
Considering the equilibrium below, which of the following is/are TRUE? CH3OH + HNO2 = CH3OH2+ + NO2- CH3OH is a base NO2 is a conjugate acid IAM. I only SXY. II only AND. I and II IKI. Neither I nor II Which of the following statements is/are ALWAYS TRUE? A higher Ksp value equates to a higher solubility regardless of the salt type When Qsp = Ksp, the system is at equilibrium CHM. I only EQU. II only LIB. I and II RIA. Neither I nor II
4. The molar absorptivities of the indicator weak acid HIn (K_{a} = 1.42 * 10 ^ - 5) and its conjugate base In at 570 were determined as epsilon(HIn) = 7120 and ε(In) = 961. The optical length b = 1.00 cm. (a) What is the absorbance of an unbuffered indicator solution having total indicator concentration 8.0 * 10 ^ - 5 (b) What is the absorbance of a buffered indicator solution having total indicator concentration 8.0 * 10 ^ - 5 and pH = 6.5 .
The indicator cresol red has Kₐ=3.5X10⁻⁹. Over what ap-proximate pH range does it change color?