Acetic acid
Jump to navigation
Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
Uses
- Generically, as an acid which can be produced fairly easily
- Feedstock for acetic anhydride
- Source acid for all acetate compounds
- Pharm: Ear/nose/throat topical application
Natural occurence
- Main Article: Vinegar
Acetic acid does occur naturally as a secondary metabolite of acetobacter as it consumes ethanol.
- CH3CH2OH + O2{acetobacterCH3COOH + H2OΔH=-490kJ30°C}→
Hazards
- Bronchial & skin irritant
Character
Temperature (°C) | Mol% water in liquid | Mol% water in vapor |
---|---|---|
100.8 | 0.865 | 0.907 |
101.7 | 0.755 | 0.817 |
102.4 | 0.675 | 0.770 |
103.5 | 0.5725 | 0.678 |
104.2 | 0.520 | 0.635 |
105.6 | 0440 | 0.556 |
107.7 | 0.305 | 0.420 |
- The eutectic point is -27°C / 71.6% (mol/mol) / 88.3% (kg/kg).
Production
Extraction
from vinegar
distillation
- Distill vinegar, preferably at reduced pressure. The water distills over, leaving a proportional increase in concentration. The water bath is important to prevent the possible degradation or oxidation of any acetic acid vapor.
l/l extraction
- Combine vinegar with diethyl ether
- Mix well
- Allow to separate (>90% in the ether layer)
- decant off the hydrocarbon layer
- Distill off the hydrocarbons, leaving acetic acid.
Synthesis
From acetates
via sulfuric acid
- Gather 7 ubm of calcium acetate
- Gather 4 ubm of sulfuric acid
- Combine the acetate and acid, producing a solution of acetic acid and calcium sulfate
- Ca(CH3COO)2 + H2SO4{2 CH3COOH(l) + CaSO4(diss.)otp}→
- Ca(CH3COO)2 + H2SO4
- Distill the solution, precipitating out the calcium sulfate
- CH3COOH(l) + CaSO4(dis){CH3COOH(v) + CaSO4(s)120°C}→
- CH3COOH(l) + CaSO4(dis)
via hydrochloric acid
- As with sulfuric acid, the same reaction can be done with hydrochloric acid producing the more useful calcium chloride as a byproduct.
- Ca(CH3COO)2 + 2 HCl → CaCl2 + 2 CH3COOH
via sodium bisulfate
- Gather equimolar amounts of anhydrous sodium acetate and sodium bisulfate
- Grind and thoroughly mix
- Dry-distill
- NaCH3COO(s) + NaHSO4(s){Na2SO4(s) + CH3COOH(v)heat}→
- NaCH3COO(s) + NaHSO4(s)
- The residue is sodium sulfate
- The distillate is acetic acid
Purification
- Wash with pentane or hexane - immiscible
Testing
(density of solution)-1
========================= 0.049 |
Storage
Disposal
See Also
References
- ↑ SEBASTIANI, E.; LACQUANITI, L. (1967) "Acetic acid-water system thermodynamical correlation of vapor-liquid equilibrium data"
Chemical Engineering Science 22; pp1155-l162. Pergamon Press Ltd.