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A ___ is the sodium or potassium salt of a long-chain fatty acid.
soap
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Most solid soaps are ____ salts.
sodium
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The starting materials are fats or oils, which are the ______ of the fatty acids.
Glycerol esters
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What are the princple reactants in this experiment?
Cottonseed oil (a typical cooking oil) and a concentrated solution of sodium hydroxide
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_____ is used in this experiment to serve as a common solvent for the reactants and hence to speed up the reaction.
Ethanol
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Is ethanol is used in commerical soap-making operations?
no
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What is soap making called?
saponification
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What is the saponification reaction in this experiment?
oil -> glycerol + sodium salt
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The sodium salts of the long-chain fatty acids are typical ____ agents.
surface-active
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Soap has a polar end which is _______ and a long nonpolar chain which is _______.
hydrophilic; hydrophobic
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As consequence of soap's nonpolar and polar ends, they can form ______ by suspending oil in water when their nonpolar end is in the oil and their polar end group is in water.
emulsions
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The _____ of kerosene in water by means of soap is done via emulsions.
emulsification
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What are 3 common metal salts that can form insoluble precipitates with the long-chain fatty acids?
Calcium, magnesium, and iron
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Hard water kills soap; what is "hard water"?
water containing appreciable amounts of dissolved calcium, magnesium, or iron salts
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State on safety precaution to be taken when using (1) sodium hydroxide solution, and (2) ethanol.
(1) wear safety glasses, (2) be careful around flames
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Describe how to determine safely if all ethanol has evaporated from the reaction mixture.
Wait until the alcohol smell has disappeared
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What class of natural compounds serves as the starting material for the prepartion of soap when reacted with NaOH?
the glycerol esters of fatty acids (fats and oils)
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How is the soap recovered as a solid product from the solution containing the other products of the reaction?
Using the process called "salting out", which involves mixing the saturated sodium chloride solution into the soap prepartion.
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