uestion 8 Based on the results obtained in the following table, which indicator has approximately a pka of 4? Acid-base Color Standards Sample indicator A RRR Y Y Y Y Y Y Y Y Y Y RR RR O Y B Y Y Y Y Y Y R B B RRR B R R Y Y Y CCC RRRR pH 1 2 3 4 5 6 7 8 10 11 12 13 14 ? LEGEND: R-red Y-yellow 0-orange B-blue V-violet C-colorless P-pink O D O A O B B. P. RI >

uestion 8 Based on the results obtained in the following table, which indicator has approximately a pka of 4? Acid-base Color Standards Sample indicator A RRR Y Y Y Y Y Y Y Y Y Y RR RR O Y B Y Y Y Y Y Y R B B RRR B R R Y Y Y CCC RRRR pH 1 2 3 4 5 6 7 8 10 11 12 13 14 ? LEGEND: R-red Y-yellow 0-orange B-blue V-violet C-colorless P-pink O D O A O B B. P. RI >

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter24: Introduction To Spectrochemical Methods

Section: Chapter Questions

Problem 24.1QAP

See similar textbooks

Similar questions

Phenolphthalein is a commonly used indicator that is colorless in the acidic form (pH 8.3) and pink in the base form (pH 10.0). It is a weak acid with a pKa of 8.7. What fraction is in the acid form when the acid color is apparent? What fraction is in the base form when the base color is apparent?
Explain why an acid-base indicator changes color over a range of pH values rather than at a specific pH.
The indicator dinitrophenol is an acid with a Ka of 1.1104. In a 1.0104 -M solution, it is colorless in acid and yellow in base. Calculate the pH range over which it goes from 10% ionized (colorless) to 90% ionized (yellow).
What is an acidbase indicator? Define the equivalence (stoichiometric) point and the end point of a titration. Why should you choose an indicator so that the two points coincide? Do the pH values of the two points have to be within 0.01 pH unit of each other? Explain.
Phenolphthalein indicator is a weak acid with Ka = 10-9 mol/dm-3. It is colourless while its conjugate base is pink in solution. Define the term" WEAK ACID"
If the pKa of the indicator is approximately 6, to which of the following equivalence point will it be most suitable? pH 5 pH 10 pH 4 pH 13
The acid–base indicator bromcresol green is a weak acid.The yellow acid and blue base forms of the indicator arepresent in equal concentrations in a solution when the pHis 4.68. What is the pKa for bromcresol green?
If the pKa of the indicator is approximately 6, to which of the following equivalence point will it be most suitable? a. pH 10 b. pH 5 c. pH 4 d. pH 13
Phenol red is a common acid-base indicator. It has a pKa equal to 8.000. It's undissociated form is yellow and its anionic form is violet. What color would a solution containing phenol red solution if the pH is 7.50? yellow yellow-orange red-orange red-violet violet
In the experiment, we used titration to determine the total acid content ofsamples, which we reported in terms of molarity. Reporting acidity through pHmeasurements is quite different, in that we can only measure the amount of theacid in its ionized form. You were tasked to investigate a clear aqueous solutionof an unknown monoprotic acid. You decided to use two methods togather data.Method 1 – TITRATION: A 10. mL aliquot of the sample was diluted with 25 mLdistilled water. Two drops of phenolphthalein were added and then it was titrated3.54 mL of 0.048 M standardized NaOH to the endpoint.Method 2 – pH STRIP: You took 1 mL of the sample and used a pH strip toestimate the pH, which turned out to be around 3.3. Another 1 mL of the samplewas diluted with 9 mL of water. The pH was taken again and is now around 3.8.a) Calculate the molarity of the acid using the titration data.b) If we assume that the titrated unknown is a strong acid, predict thepH of the sample.c) Using pH strip results,…
C10H12NO4N is a weak base and has a Kb of 1.58x10-10. One, 0.650g, is dissolved in 235mL of distilled water. a. What is the initial concentration, in units of molarity, of the zalcitabine? b. Write an expression for Kb for zalcitabine. c. What are the equilibrium concentrations of the products and reactant? d. What is the pH, pOH, and % ionization of this weak base?
Phenolphthalein has a pKa of 9.7. It is colorless in its acid form and pink in its basic form. For each of the values of pH, calculate [In-]>[HIn] and predict the color of a phenolphthalein solution. a. pH = 2.0 b. pH = 5.0 c. pH = 8.0 d. pH = 11.0