4. Select/choose an appropriate chemical indicator for the following titration set-up and explain why you chose that indicator: a. weak acid + strong base if pH at equivalence pt = 9 b. Weak base + strong acid if pH at equivalence pt = 5 c. Strong acid + strong base if pH at equivalence pt = 7 Indicator Acid Alkaline Approximate pKa(In) pH range (HIn) (In") Methyl Violet Thymol Blue Methyl Orange Bromophenol Blue Methyl Red Bromocresol Purple Bromothymol Blue yellow blue 0.0 - 1.6 red yellow yellow 1.2 - 2.8 1.7 red 3.1 - 4.4 3.4 yellow red blue 2.9 - 4.6 4.0 yellow purple blue 4.2 - 6.3 5.1 yellow yellow yellow yellow colourless 5.2 - 6.8 6.0 - 7.6 6.8 - 8.4 6.3 7.0 Phenol Red red 7.9 Thymol Blue Phenolphthalein blue 8.0 - 9.6 8.9 red 8.3 - 10.0 9.4 A

4. Select/choose an appropriate chemical indicator for the following titration set-up and explain why you chose that indicator: a. weak acid + strong base if pH at equivalence pt = 9 b. Weak base + strong acid if pH at equivalence pt = 5 c. Strong acid + strong base if pH at equivalence pt = 7 Indicator Acid Alkaline Approximate pKa(In) pH range (HIn) (In") Methyl Violet Thymol Blue Methyl Orange Bromophenol Blue Methyl Red Bromocresol Purple Bromothymol Blue yellow blue 0.0 - 1.6 red yellow yellow 1.2 - 2.8 1.7 red 3.1 - 4.4 3.4 yellow red blue 2.9 - 4.6 4.0 yellow purple blue 4.2 - 6.3 5.1 yellow yellow yellow yellow colourless 5.2 - 6.8 6.0 - 7.6 6.8 - 8.4 6.3 7.0 Phenol Red red 7.9 Thymol Blue Phenolphthalein blue 8.0 - 9.6 8.9 red 8.3 - 10.0 9.4 A

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

7. Refer to the following table: Table 2-2. Change in pH of 0.2 M Acetate Buffer after addition of Acid or Base [Base]:[Acid] 0.005:0.195 Addition pH HC1 0.095 mol 3.1 HC1 0.075 0.025:0.175 3.9 HС1 0.05 НС1 0.025 0.05:0.15 4.2 0.075:0.125 4.5 0.1:0.1 0.125:0.075 4.7 NaOH 0.025 mol 4.9 NaOH 0.05 mol 0.15:0.05 5.2 NaOH 0.75 mol 0.175:0.025 5.5 NaOH 0.095 mol 0.195:0.005 6.3 a. Calculate the pH of a 0.2 M acetate buffer (a solution containing 0.1 mol L-' acetic acid and 0.1 mol L-1 sodium acetate), given that the pKa of acetic acid is 4.7. b. What would be the pH value after adding 0.05 mol of NaOH to 1 L of 0.2 mol L1 acetate buffer? c. Compare the pH value in (b) with that obtained after adding 0.05 mol NAOH to 1 L of water (a simple solution of 0.05 mol L-' NaOH). d. How much acid or base can be added to 1 L of the 0.2 M acetate buffer so that the pH does not change appreciably (i.e., what is its buffer range)?
12. A 1.00 L buffer solution is 0.150 M in weak organic acid HC₂H5O₂ and 0.250 M in LiC7H5O2. Calculate the pH of the solution after the addition of 0.01 mol HCI. The Ka for HC₂H5O2 is 6.5 x 10-5. (hint: the total volume after adding 100ml of HCl solution turn to 1.00L+100ml = 1.10 L, so molarity calculation should be based off the new volume)
Calculate the pH for each of the cases in the titration of 25.0 mL of 0.110 M pyridine, C₁H₁N(aq) with 0.110 M HBr(aq). The Kb of pyridine is 1.7 x 10-⁹. before addition of any HBr pH = after addition of 12.5 mL of HBr after addition of 16.0 mL of HBr after addition of 25.0 mL of HBr after addition of 35.0 mL of HBr 9.31 pH = pH = pH = pH = 5.23 4.63 Incorrect 11.65 Incorrect 1.33 Incorrect
Please answer; they were all the same choices.
Calculate the pH during the titration with NaOH after addition of: a) 50.00 mL of 0.1000 mol L-1 NaOH to 50.00 mL of 0.1000 mol L-1 CH3COOH (Ka= 1.75 x 10-5). b) Based on the table below, which indicator (A, B or C) is most appropriate to monitor this titration? Explain. Indicator A B C pKIndicator 3.8 9.3 5.0 Actual Transition Range (pH) 3.0 to 4.6 3.0 to 4.6 4.4 to 6.2
Be sure to answer all parts. Use the figure below to find an indicator for these titrations: (a) 0.10 M CH3NH₂(Kb = 4.4 x 10-4) with 0.10 M HCI (select) (b) 0.50 M HI with 0.10 M KOH (select) Crystal violet Thymol blue 2,4-Dinitrophenol Bromophenol blue Bromocresol green Methyl red Alizarin 0 Bromothymol blue Phenol red Phenolphthalein Alizarin yellow R 11 12 13 14
Answer using this data for the remaining questions on this page: For 1.0L of an acetic acid solution: Ka = 1.8 x 10-5 and [HA] = 0.250M 2. Calculate the pH of the solution. 3. What is the pka? 4. Calculate the pH of the solution if you make it a buffer by adding enough solid sodium acetate to make the concentration of acetate ion equal to 0.35M. The volume of the solution does not change. 5. What is the new concentration of [HA] if 2.0mL of 5.00M of HCI is added to 1.000L of the solution above? 6. What is the new pH?