Buffer Preparation Name: Part A - Measuring pH (record concentrations based on pH measurements with 3 sig figs) Solution pH Calculated [H+] pOH Calculated [OH-] 1.0M Acetic Acid 1.0M Sodium Acetate...

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Buffer Preparation Name: Part A - Measuring pH (record concentrations based on pH measurements with 3 sig figs) Solution pH Calculated [H+] pOH Calculated [OH-] 1.0M Acetic Acid 1.0M Sodium Acetate 1.0M Ammonia 1.0M Ammonium Chloride 1.0M Phosphoric Acid 1.0M Sodium Phosphate Distilled Water Distilled Water + 1.0M HCl Distilled Water + 1.0M NaOH Acetate Buffer Acetate Buffer + 1.0M HCl Acetate Buffer + 1.0M NaOH Ammonia Buffer Ammonia Buffer + 1.0M HCl Ammonia Buffer + 1.0M NaOH Phosphate Buffer Phosphate Buffer + 1.0M HCl Phosphate Buffer + 1.0M NaOH Calculations #1). Use your pH value to calculate the [H+] of the 1.0M Acetic Acid. Show your work. #2). What is the % Ionization of Acetic acid? Show your work. #3). Use your pH value to calculate the [Acetate] of the 1.0M Acetic Acid. Show your work. #4). What is the calculated Ka for Acetic Acid? Show your work #5). Use your pH value to calculate the [NH+] of the 1.0M Ammonia. Show your work. #6). What is the % Ionization of Ammonia? Show your work. #7). What is the calculated Kb for Ammonia? Show your work. #8). If you were to add 2.1500g of solid Sodium Acetate Trihydrate to 100.00mL your Acetate buffer solution, complete the following questions and ICE table. 8a). How many moles of Acetate ion are added? Show your work. 8b). What is the molarity of these additional acetate ions? Show your work 8c). What is the initial pH of your Acetate Buffer? [CH3COOH] [CH3COO-] [H+] Eq. Conc. Of Acetate Buffer Additional Acetate (I)nitial (C)hange (E)quilibrium Complete the ICE above table. Show your work. You may need to use the Quadratic Formula. What is the Final pH of new solution: _____________ #9. Would the resulting solution still be a Buffer? Yes or No, explain your answer. Part B - Preparing & Testing Buffers Complete the Table of Conjugate Acids & Bases Complete the table below by indicating the conjugate base for the given conjugate acid and the conjugate acid for the given conjugate base. Conjugate Acids Conjugate Bases Name Formula Name Formula Acetate Nitric Acid Dihydrogen Phosphate Dihydrogen Phosphate H2O Water NH4+ Buffering Capacity Complete the table below to determine which is the better buffer for the given conditions Acetate Buffer Phosphate Buffer Ammonia Buffer Initial pH pH After Adding HCl Change in pH pH After Adding NaOH Change in pH #10). Which buffer has a better buffering capacity for bases? Explain your answer. #11). Which buffer has a better buffering capacity for acids? Explain your answer. Part C – Titration of Phosphoric Acid Obtain the pH of Phosphoric Acid after each addition of NaOH Volume of NaOH pH Volume of NaOH pH 0.00mL 13.00mL 1.00mL 14.00mL 2.00mL 15.00mL 3.00mL 16.00mL 4.00mL 17.00mL 5.00mL 18.00mL 6.00mL 19.00mL 7.00mL 20.00mL 8.00mL 21.00mL 9.00mL 22.00mL 10.00mL 23.00mL 11.00mL 24.00mL 12.00mL 25.00mL Prepare a graph of pH on the Y-Axis vs mols NaOH on the X-Axis #16). What is the first Equivalence Point in the Titration Curve? #17). What is the net ionic equation for the first step in the titration curve? #18). What is the second Equivalence Point in the Titration Curve? #19). What is the net ionic equation for the second step in the titration curve? Attach your graph below undefined: undefined_2: undefined_3: undefined_4: undefined_5: undefined_6: undefined_7: undefined_8: undefined_9: undefined_10: undefined_11: undefined_12: undefined_13: undefined_14: undefined_15: undefined_16: undefined_17: undefined_18: undefined_19: undefined_20: undefined_21: undefined_22: undefined_23: undefined_24: undefined_25: undefined_26: undefined_27: undefined_28: undefined_29: undefined_30: undefined_31: undefined_32: undefined_34: undefined_36: undefined_37: undefined_38: What is the Final pH of new solution: Text1: Text2: Text3: Text4: Text5: Text6: Text7: Text8: Text9: Text10: Text11: Text12: Text13: Text14: Text15: Text16: Text17: Text18: Text19: Text20: Text21: Text22: Text23: Text24: Text25: Text26: Text27: Text28: Text29: Text30: Text31: Text32: Text33: Text34: Text35: Text36: Text37: Text38: Text39: Text40: Text41: Text42: Text43: Text44: Text45: Text46: Text47: Text48: Text49: Text50: Text51: Text52: Text53: Text54: Text55: Text56: Text57: Text58: Text59: Text60: Text61: Text62: Text63: Text64: Text65: Text66: Text67: Text68: Text69: Text70: Text71: Text72: Text73: Text74: Text75: Text76: Text77: Text78: Text79: Text80: Text81: Text82: Text83: Text84: Text85: Text86: Text87: Text88: Text89: Text90: Text91: Text92: Text93: Text94: Text95: Text96: Text97: Text98: Text99: Text100: Text101: Text102: Text103: Text104: Text105: Text106: Text107: Text108: Text109: Text110: Text111: Text112: Text113: Text114: Text115: Text116: Text117: Text118: Text119: Text120: Text121: Text122: Text123: Text124: Text125: Text126: Text127: Text128: Text129: Text130: Image131_af_image: http://chemcollective.org/vlab/99 stimulation link for buffer preparation. https://www.youtube.com/watch?v=cp5KRbkgo-Y buffer preparation video.
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Answered 2 days AfterJul 08, 2021

Answer To: Buffer Preparation Name: Part A - Measuring pH (record concentrations based on pH measurements with...

Neelakshi answered on Jul 11 2021
128 Votes
Part A - Measuring pH
    Solution
    pH
    Calculated [H+ ]
    pOH
    Calculated [OH- ]
    1.0M Acetic Acid
    2.37
    0.00417
    11.63
    2.42 * 10-2
    1.0M Sodium Acetate
    9.38
    4.20 * 10-10
    4.62
    0.0000240
    1.0M Ammonia
    11.62
    2.40* 10-12
    2.38
    0.00424
    1.0M Ammonium Chloride
    4.63
    0.0000237
    9.37
    4.27* 10-10
    1.0M Phosphoric Acid
    3.06
    
    9.94
    
    1.0M Sodium Phosphate
    6.0
    
    7.0
    
    Distilled Water
    7.0
    1.0048 * 10-7
    7.0
    1.0048 * 10-7
    Distilled Water + 1.0M HCl
    1.71
    0.0196
    12.29
    5.15* 10-13
    Distilled Water + 1.0M NaOH
    12.29
    5.15* 10-13
    1.71
    0.0196
    Acetate Buffer
    4.10
    0.0000793
    9.9
    1.27* 10-7
    Acetate Buffer + 1.0M HCl
    2.58
    0.00061
    11.42
    3.86* 10-12
    Acetate Buffer + 1.0M NaOH
    4.54
    0.0000285
    9.46
    3.54* 10-10
    Ammonia Buffer
    10.13
    7.49* 10-11
    3.87
    0.000135
    Ammonia Buffer + 1.0M HCl
    9.33
    4.70* 10-10
    4.67
    0.0000215
    Ammonia Buffer + 1.0M NaOH
    12.11
    7.76710* 10-13
    1.89
    0.0130
    Phosphate Buffer
    2.50
    
    10.5
    
    Phosphate Buffer + 1.0M HCl
    
    
    
    
    Phosphate Buffer + 1.0M NaOH
    
    
    
    
1). Use your pH value to calculate the [H+] of the 1.0M Acetic Acid. Show your work.
Answer:
By using pH=−log[H+]
[H+]=10−pH
[H+]=10−2.37
[H+]=0.00426579
[H+]=4.26 *10−3 M
2). What is the % Ionization of Acetic acid? Show your work.
Answer:
CH3COOH dissociates to a small extent:
CH3COOH ↔ CH3COO- + H+
Hence Ka will be...
Ka = [H+] [[CH3COO-] / [CH3COOH]
Because [H+] =[CH3COO-] and dissociation is very small, equation can be written as
Ka = [H+]² / 0.1
Ka = 1.8*10^-5
1.8*10^-5 = [H+]² / 0.1
[H+]² = (1.8*10^-5)* 0.1
[H+]² = 1.8*10^-6
[H+] = 0.0013M
% dissociation = 0.0013/0.1*100 = 1.34%
3). Use your pH value to calculate the [Acetate] of the 1.0M Acetic Acid. Show your work.
Answer:
As CH3COOH is weak acid.
Because [H+] =[CH3COO-] and dissociation is very small.
Hence, [H+] =[CH3COO-]
[H+]=0.00426579
[H+]=4.26 *10−3 M
4). What is the calculated Ka for Acetic Acid? Show your work.
Answer:
CH3CO2H + H2O <--> CH3CO2− + H3O+
Acetic Acid (CH3CO2)H) Hydronium Ions (H3O+) Acetate Ions ( CH3CO2-)
Change -x M +x M +x M
Equilibrium (0.9 - x) M x M x M
The...
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