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

Chemical Reaction sapon.htm sapon.htm

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

Soap in the Industrial Revolution Soap production remained a domestic activity until the end of the 18 th 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).

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)

The Fermentation Industry An Introduction: Distillation and Brewing

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 = CH 4 – Also called wood alcohol since it is the major product of the fermentation of wood – CH 3 OH – Poisonous when ingested

Alcohol The next smallest is ethyl alcohol of ethanol – From the alkane ethane C 2 H 6 – also called grain alcohol since it is produced when grain ferments – C 2 H 5 OH – Is the alcohol present in alcoholic drinks There are many other alcohols: propanol, butanol, etc

From Grain to Alcohol Chemical Reaction (C 6 H 10 O 5 ) n + nH 2 O  (C 6 H 12 O 6 ) 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) C 6 H 12 O 6  2C 2 H 5 OH + 2CO 2 Glucose or sugar decomposes to ethanol and carbon dioxide in the presence of yeast and absence of oxygen (anaerobic oxidation). This is called fermentation.

Combustion of Sugar Chemical Reaction In the presence of oxygen, sucrose burns to give water and carbon dioxide. C 6 H 12 O 6 + 6O 2  6H 2 O + 6CO 2

A Comparison BeerWineSpirits Historical Reference7000 BC6000 BC3000 BC Water Fermentable Material (e.g.) Starch: Malted barley Sugar: Grapes, other fruits Distilled fermented grapes, grain, etc Brewer’s YeastYeastDistillation FlavoringsHopsOther grapesOrange, hazelnut Usual ABV (alcohol by volume) 4-6% AVB10-14% ABV30-95% OtherpH = tartaric, malic, citric

Ideal Liquid Solution Phase diagram for “ideal” 2-component liquid system. – /idealpd.html#top /idealpd.html#top – Fractional distillation can lead to 100% purification. – /idealfract.html#top /idealfract.html#top – Wikipedia on Benzene-Toluene Phase Diagram

Benzene and Toluene Form an Ideal Solution Benzene boils at 80.1 o C and toluene at o C. 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?

Benzene and Toluene Phase Diagram and Separating two Components

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

Water-Ethanol Phase Diagram s/petrology/teaching_examples/Kitchen_Text. pdf s/petrology/teaching_examples/Kitchen_Text. pdf