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Soap. Soap. Known to exist in 2800 BC Mt. Sapo : animal fats + wood ashes or kelp, + clay + heat  good cleaning mixture = soap + glycerine This is the sapo nification reaction. Plant or animal fat + alkali + heat  K or Na salts of fatty acids. Clow p 116-117. Chemical Reaction.

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  1. Soap

  2. Soap • Known to exist in 2800 BC • Mt. Sapo: animal fats + wood ashes or kelp, + clay + heat  good cleaning mixture = soap + glycerine • This is the saponification reaction. • Plant or animal fat + alkali + heat  K or Na salts of fatty acids. • Clow p 116-117

  3. Chemical Reaction • http://chemistry.about.com/library/weekly/blsapon.htm

  4. How do soaps function? • Soaps are • K or Na salts of fatty acids • Soluble in water. • Surfactants or surface active agents which lower the surface tension of water; “wets” water. • Negatively charged. • Basic; can react with acid stains, dirt. • Fatty acid tail (long carbon backbone with H atoms) is attracted to oils and fats. • Acid end is attracted to water

  5. Soap in the Industrial Revolution • Soap production remained a domestic activity until the end of the 18th c. I.e. the industry developed slowly. • Not a component of a natural resource. • Product of chemical reaction which had to be analyzed, tested and reproduced. • Great variety of starting materials were a source of confusion (Dundonald again, p. 118; record his contributions to various chemical industries).

  6. Soap Industry • Once the science ( chemical reaction, required reactants, desired products, conditions) was understood, the soap industry grew (Clow p 119) from 1830 (Clow graph p. 124). • Clow p. 120 diagram • Chemistry rules (Clow p 125, 126, 127)

  7. The Fermentation Industry An Introduction: Distillation and Brewing

  8. Alcohol • Alcohol describes a broad class of organic compounds that contain the –OH functional group, know as the hydroxyl group. • The smallest alcohol is methyl alcohol or methanol • From the alkane methane = CH4 • Also called wood alcohol since it is the major product of the fermentation of wood • CH3OH • Poisonous when ingested

  9. Alcohol • The next smallest is ethyl alcohol of ethanol • From the alkane ethane C2H6 • also called grain alcohol since it is produced when grain ferments • C2H5OH • Is the alcohol present in alcoholic drinks • There are many other alcohols: propanol, butanol, etc

  10. From Grain to AlcoholChemical Reaction • (C6H10O5)n + nH2O  (C6H12O6)n Starch from cellulose (plant matter) is converted to glucose via hydrolysis or addition of water. Methods include the action of enzymes (major commercial method) and reaction with acid (historic method) • C6H12O6 2C2H5OH + 2CO2 Glucose or sugar decomposes to ethanol and carbon dioxide in the presence of yeast and absence of oxygen (anaerobic oxidation). This is called fermentation.

  11. Combustion of SugarChemical Reaction • In the presence of oxygen, sucrose burns to give water and carbon dioxide. C6H12O6 + 6O2 6H2O + 6CO2

  12. A Comparison

  13. Ideal Liquid Solution • Phase diagram for “ideal” 2-component liquid system. • http://www.chemguide.co.uk/physical/phaseeqia/idealpd.html#top • Fractional distillation can lead to 100% purification. • http://www.chemguide.co.uk/physical/phaseeqia/idealfract.html#top • Wikipedia on Benzene-Toluene Phase Diagram

  14. Benzene and Toluene Form an Ideal Solution • Benzene boils at 80.1 oC and toluene at 110.6 oC. • The B-B IMF are nearly the same as the T-T IMF and also the B-T IMF; these are the conditions for an ideal solution. • Benzene and Toluene can be separated completely by fractional distillation – note different BPs. Which boils first?

  15. Benzene and Toluene Phase Diagram and Separating two Components

  16. Why 95% ABV? • Phase diagram for water and alcohol (non ideal). • Water boils at 100 oC and ethanol at 78.4 oC. • Water and ethanol form a low boiling azeotrope at 78.1 oC and 95.6% ethanol and 4.4% water. • Limit to separation by fractional distillation

  17. Water-Ethanol Phase Diagram • http://serc.carleton.edu/files/NAGTWorkshops/petrology/teaching_examples/Kitchen_Text.pdf

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