Hydrolysis Of Methyl Acetate

22,663 views

Published on

CIT-ChE Phychem Reports

0 Comments
5 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
22,663
On SlideShare
0
From Embeds
0
Number of Embeds
6
Actions
Shares
0
Downloads
171
Comments
0
Likes
5
Embeds 0
No embeds

No notes for slide

Hydrolysis Of Methyl Acetate

  1. 1. Physical Principles II CEBU CITY Chemical Engineering Department Name: Juphil Lamanilao Date: October 15, 2009 Course & Yr: BSChE-4 I.TITLE: Hydrolysis of Methyl Acetate II.OBJECTIVE: • To determine the specific rate constant at two or more given temperatures. III.APPARATUS: Thermostat at 25ºC & 35 ºC, (3) 250-ml Erlenmeyer flasks, (2) 125-ml Erlenmeyer flasks, 5-ml pipette, 100-ml pipette, stop watch, Ethyl acetate, 2 liters 0.1N NaOH, 500 ml 0.1N HCl, distilled water, ice. IV.SKETCH: Hydrolysis of Methyl Acetate 1
  2. 2. Physical Principles II V.TABULATED DATA & RESULTS: @ 25ºC VHCl(ml) VH2O(ml) Valiqout(ml) VNaOH(ml) t(min) 1 50 50 5 3.4 1.59 2 50 50 5 3.5 2.44 3 50 50 5 3.7 3.07 @ 35 ºC VHCl(ml) VH2O(ml) Valiquot(ml) VNaOH(ml) t(min) 1 50 50 5 4.2 2.42 2 50 50 5 5.0 1.89 @ 25ºC 1st run 2nd run 3rd run @35ºC 1st run 2nd run NNaOH(mol) 0.1811 0.1864 0.1970 NNaOH(mol) 0.223 0.2663 NHCl(mol) 0.0050 0.0050 0.0050 NHCl(mol) 0.0050 0.0050 NHOAc(mol) 0.1761 0.1814 0.1920 NHOAc(mol) 0.2187 0.2613 Co(mol) 0.5113 0.5113 0.5113 Co(mol) 0.5113 0.5113 C(mol) 0.3352 0.3299 0.3193 C(mol) 0.2926 0.2500 t(min) 10 10 10 t(min) 10 10 k(s-1) 0.000704 0.000730 0.000785 k(s-1) 0.000930 0.00120 Temp(ºC ) t(min) EtOAc 25 7.32 EtOAc 35 5.93 The average constant K, calculated from the equation lnCo-lnC = kt, was found to be 0.000740s-1 at 25ºC and 0.00108s-1 at 35ºC, both at constant 10 minute interval. As the temperature increases, the specific rate also increases and the final concentration is inversely proportional to the specific rate constant. VI.SAMPLE COMPUTATIONS: NNaOH = NHCl + NHOAc NHOAc = 0.1761 mol NNaOH = 2.13 g/ml * 3.4 ml * mol/40g = 0.1811 mol NHCl = 0.1 eq/1000mol * mol/eq * 50 ml = 0.005 mol NHOAc = NEtOAc consumed C = Co - NHOAc C = 50 ml * 0.901 g/ml * mol/88.105g = 0.3352 mol C = 0.5113 mol – 0.1760 mol = 0.3352 mol Hydrolysis of Methyl Acetate 2
  3. 3. Physical Principles II lnCo – lnC = kt ln0.5113 – ln0.3352/600 s = k = 0.0007040s -1 VII.DATA ANALYSIS: The experimental value obtained for the specific rate constant at 25оC approaches 0.000740s-1 for (3) runs @ 10 minute interval on the other hand the obtained specific rate constant value at 35оC approaches 0.00108s-1 for the same time interval. As temperature increases the specific rate constant also increases, which pertains that temperature is directly proportional to specific rate constant. From the results obtained, the final concentration (C) is a function of time (t). Plotting lnC against time, the reaction will cease and reactants utterly dissociate. VIII.APPLICATION TO ChE: In the production of polyvinyl alcohol, methyl acetate is typically produced as a by-product. In order to produce polyvinyl alcohol at a reasonable cost, it is necessary to recover acetic acid and methanol from the methyl acetate so produced. This is typically done by the hydrolysis of methyl acetate with water to produce a mixture of methyl acetate, methanol, acetic acid and water, which mixture is subsequently separated to isolate the acetic acid and methanol. Effort has long been directed toward the improvement of the efficiency of this reaction and the subsequent separation. Since the hydrolysis process is an equilibrium reaction, it can be driven to greater acetic acid production by the addition of water. However, it is also desirable to keep the concentration of water to a minimum, since any water added to the system must later be removed from the reaction products. This removal is generally carried out by a distillation process in which any added volume increases the energy consumption. Other application involved the inversion of cane sugar and irradiation of strong infrared from free electron laser source IX.CONCLUSION: The hydrolysis of methyl acetate is a reversible reaction as shown; MeAc + H2O ↔ HAc + MeOH. In dilute aqueous solution, water is present in such excess that its concentration remains unchanged during the reaction, and if the experiment is carried in a solution of a strong acid catalyst, the formation of acetic acid will not effectively change the concentration of hydronium ions. Also, the ice used to quench the reaction mixture Hydrolysis of Methyl Acetate 3
  4. 4. Physical Principles II should be made with distilled water otherwise it increases the ionic strength of the solutions as it melts due to which dissolved salts go into the solution. Hydrolysis of Methyl Acetate 4

×