User:Karlena L. Brown/Notebook/PVOH Research/2012/11/09: Difference between revisions
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'''MW NaHCO3: 204.24 g/mol''' | '''MW NaHCO3: 204.24 g/mol''' | ||
1M KHP × 0.1L H<sub>2</sub>O × (204.24g KHP/1 mol KHP)= 20.424g KHP | 1M KHP × 0.1L H<sub>2</sub>O × (204.24g KHP/1 mol KHP)= 20.424g KHP | ||
{| {{table}} | |||
| align="center" style="background:#f0f0f0;"|'''Sample #''' | |||
| align="center" style="background:#f0f0f0;"|'''Original KHP Amount Dried (g)''' | |||
|- | |||
| 1||6.8079 | |||
|- | |||
| 2||6.8075 | |||
|- | |||
| 3||6.8076 | |||
|} | |||
==Titration Procedures and Preparations== | ==Titration Procedures and Preparations== | ||
# In a clean burette, pour in the 0.2M NaHCO<sub>3</sub> solution until it reaches the top | # In a clean burette, pour in the 0.2M NaHCO<sub>3</sub> solution until it reaches the top | ||
# Turn the stopcock at the bottom of the burette to allow the solution to pass through the tip | # Turn the stopcock at the bottom of the burette to allow the solution to pass through the tip | ||
# | # In a clean beaker, run the solution from the burrette until 0.2M NaHCO<sub>3</sub> solution volume reaches the 0.00mL calibration mark | ||
# Record the initial starting point and then turn on the stir plate beneath the burette | # Record the initial starting point and then turn on the stir plate beneath the burette | ||
# Next, place one of the acetylation PVOH solutions onto the stir plate | # Next, place one of the acetylation PVOH solutions onto the stir plate | ||
# While stirring the PVOH solution, add ~2 drops of bromothymol blue indicator | # While stirring the PVOH solution, add ~2 drops of bromothymol blue indicator | ||
# Begin titrating by turning the stopcock on the burette allowing the 0.2M NaHCO<sub>3</sub> solution to steadily stream out | # Begin titrating by turning the stopcock on the burette allowing the 0.2M NaHCO<sub>3</sub> solution to steadily stream out | ||
# Slow the pace of the 0.2M NaHCO<sub>3</sub> to drops when the PVOH solution begins to turn red in color | # Slow the pace of the 0.2M NaHCO<sub>3</sub> solution to drops when the PVOH solution begins to turn red in color | ||
# Once the solution completely to turns red, stop titrating by turning the stopcock to ''' | # Once the solution completely to turns red, stop titrating by turning the stopcock to '''OFF''' position | ||
# Record the new 0.2M NaHCO<sub>3</sub> volume within the burette | # Record the new 0.2M NaHCO<sub>3</sub> volume within the burette | ||
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{| {{table}} | {| {{table}} | ||
| align="center" style="background:#f0f0f0;"|'''Titration Trial #''' | |||
| align="center" style="background:#f0f0f0;"|'''PVOH Solution (g)''' | | align="center" style="background:#f0f0f0;"|'''PVOH Solution (g)''' | ||
| align="center" style="background:#f0f0f0;"|'''Acetic Acid (mL)''' | | align="center" style="background:#f0f0f0;"|'''Acetic Acid (mL)''' | ||
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| align="center" style="background:#f0f0f0;"|'''Sodium Bicarbonate Used (mL)''' | | align="center" style="background:#f0f0f0;"|'''Sodium Bicarbonate Used (mL)''' | ||
|- | |- | ||
| 1.0043||0.26||2||0.5||42.5||42 | | 1||1.0043||0.26||2||0.5||42.5||42 | ||
|- | |- | ||
| 1.0052||0.52||2||0.0||43.2||43.2 | | 2||1.0052||0.52||2||0.0||43.2||43.2 | ||
|- | |- | ||
| 1.0027||0.78||2||0.1||42.8||42.7 | | 3||1.0027||0.78||2||0.1||42.8||42.7 | ||
|} | |} | ||
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* In addition, the 1:1 HoAc ratio solution overheated by boiling; therefore, this solution was not used for the titration analysis. | * In addition, the 1:1 HoAc ratio solution overheated by boiling; therefore, this solution was not used for the titration analysis. | ||
* Also the actual amount of NaHCO<sub>3</sub> used was 16.8046g; it is not necessary to prepare solution in a volumetric flask because the solution will be standardize to find the actual concentration. | * Also the actual amount of NaHCO<sub>3</sub> used was 16.8046g; it is not necessary to prepare solution in a volumetric flask because the solution will be standardize to find the actual concentration. | ||
* For titration, each PVOH solution after the indicator was added blue; however, when titration with the 0.2M NaHCO<sub>3</sub> solution, at equilibrium each solution turned red. | |||
* After several hours and days, it was decided that the KHP solution necessary for standardization would not form a homogeneous mixture -- KHP precipate falling out of solution -- therefore, only solid samples would be used. The KHP was not placed into solution for standardization. | |||
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__NOTOC__ | __NOTOC__ |
Revision as of 23:14, 14 December 2012
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OBJECTIVES
General Formula for reactionsPolyvinyl alcohol + [HoAc]→Polyvinyl acetate Acetylation Reaction Protocol & Film Preparation
REPEAT PROCEDURE ABOVE FOUR TIMES TO PREPARE FOUR FILMS
Acetylation Reaction Calculations1:1 HoAc Reaction Ratio: MW R-CH2CHOH-R: 44.00 g/mol MW Acetic Acid (HoAc): 60.00 g/mol 1.0g PVOH × (1 mol PVOH/44.00g PVOH) × (1 mol HoAc/1 mol PVOH) × (60.00g HoAc/1 mol HoAc) = 1.36g HoAc 1.36g HoAc × (1mL HoAc/1.05g HoAc)= 1.30mL HoAc 20% HoAc Reaction Ratio: MW R-CH2CHOH-R: 44.00 g/mol MW Acetic Acid (HoAc): 60.00 g/mol 1.0g PVOH × (1 mol PVOH/44.00g PVOH) × (0.2 mol HoAc/1 mol PVOH) × (60.00g HoAc/1 mol HoAc) = 0.27g HoAc 0.27g HoAc × (1mL HoAc/1.05g HoAc)= 0.26mL HoAc 40% HoAc Reaction Ratio: MW R-CH2CHOH-R: 44.00 g/mol MW Acetic Acid (HoAc): 60.00 g/mol 1.0g PVOH × (1 mol PVOH/44.00g PVOH) × (0.4 mol HoAc/1 mol PVOH) × (60.00g HoAc/1 mol HoAc) = 0.55g HoAc 0.55g HoAc × (1mL HoAc/1.05g HoAc)= 0.52mL HoAc 60% HoAc Reaction Ratio: MW R-CH2CHOH-R: 44.00 g/mol MW Acetic Acid (HoAc): 60.00 g/mol 1.0g PVOH × (1 mol PVOH/44.00g PVOH) × (0.6 mol HoAc/1 mol PVOH) × (60.00g HoAc/1 mol HoAc) = 0.82g HoAc 0.82g HoAc × (1mL HoAc/1.05g HoAc)= 0.78mL HoAc Titration Solution Preparation0.2M Sodium Bicarbonate (NaHCO3)solution for titration preparation:
(Actual NaHCO3 Mass= 16.8046g)
MW NaHCO3: 84.01 g/mol 0.2M NaHCO3 × 1L H2O × (84.01g NaHCO3/1 mol NaHCO3)= 16.802g NaHCO3
(Actual KHP Mass= 20.424g)
MW NaHCO3: 204.24 g/mol 1M KHP × 0.1L H2O × (204.24g KHP/1 mol KHP)= 20.424g KHP
Titration Procedures and Preparations
REPEAT THE ABOVE STEPS AGAIN FOR THE NEXT THREE PVOH SOLUTIONS
Notes
1g PVOH(1 mol PVOH unit/44.06g PVOH) x (1 mol OH/1 mol PVOH)= 0.022696 mol PVOH
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