Submitted By: Nibras Al Haq C.MSubject: ChemistryGrade: 8Silvermount International School
Soap fewer detergents are very much like soap in appearance and use and are now being widely used as soap substitutes. These are made from chemicals that are produced synthetically in a chemical factory, hence also known as,Synthetic Detergent. These are derived from fats and oils, petroleum and benzene in solution, these detergents form liquids of varying degrees of alkanet. All soap less detergents have the advantages of not reacting with the water hardness, so they wash equally well in soft and hard water. They can also be used in water that has acid or salt added i.e. for washing coloured articles where the dye tends to run.
There is a greater and wider horizon for detergents. It is generally felt that detergents are better than soaps because they:1. can be used in hard as well as soft water. They wet fabrics more quickly andreadily than soap.2. leave no soap scum or curd on tub or clothes.3. dissolve freely even in cool water, rise freely even in hard water.4. greatly increases removal of dirt.5. contain superior built-in optical bleach or brighter which eliminates the need for excessive use of chlorine bleach or for bluing.
6. are active emulsifiers of motor grease?7. are one-package products containing not only detergent but also builders,optical?bleach and water softener all built in to do a superior soil-removal job.The expense of these detergents is greater than that of soap, however, it must be remembered that half as much only is used.
How are Soapless Detergents MadeAnionic surfacants ?The chemical reacts with hydrocarbons derived from petroleum or fats and oil, produce new acids similar to fatty acids.A second reaction adds an alkali to the new acidsto produce one type of anionic surfactant molecule.
Nonionic SurfactantsNonionic surfactant molecules are produced by firstconverting the hydrocarbon to an alcohol and thenreacting the fatty alcohol with ethylene oxide.These nonionic surfactants can be reacted further withsulfur-containing acids to form another type ofanionic surfactant.
Soaps have been used for washing for thousandsof years but they always had one disadvantage. Ifused in hard water, i.e. water containing dissolved 2+ 2+minerals such as Ca or Mg , they produced an insoluble scum.Soapless detergents have similar structures to soapsbut are manufactured from aromatic hydrocarbonsobtained from crude oil. They wash just as efficientlyas soap but they do not produce scum with hard water.
You should be able to know:1. Draw the structural formula of a typical soapmolecule.2. Describe briefly the main stages involved in soap manufacture.3. State the meaning of saponification and explainwhat advantage it has over ordinary hydrolysis os anester.4. Draw the structural formula of a typical soaplessdetergent molecule.5. Describe briefly the main stages involved in themanufacture of soapless detergents.6. Explain why soapless detergents are more usefulthan soap in certain areas.7. Describe similarities and differences in structurebetween soap and soapless detergents.8. Explain what is meant by the term detergent.9. Describe how detergents remove grease andact as emulsifying agents.