Grease, dissolving

Potassium and sodium salts of long chain carboxylic acids form micelles that dissolve grease (Section 19 5) and have cleansing properties The carboxylic acids obtained by saponification of fats are called fatty acids... 

Commercially available drain cleaners such as Drano and Liquid-Plumr all contain sodium hydroxide (NaOH) as an active ingredient for dissolving grease J1-5 Crystal drain cleaners contain the solid form of sodium hydroxide, while liquid drain cleaners are strong solutions of dissolved sodium hydroxide. In addition,... 

A compound able to dissolve grease by forming micelles is called a detergent. Naturally occurring detergents are also called soaps. 

Aqueous cleaning, in which spraying of aqueous acidic or alkaline detergent solutions is followed by normal and deionized water rinses. Strong detergents dissolve greases, oils and possibly oxides. It is necessary to rinse thoroughly to avoid later attacks. 

In the case of drycleaning, the aqueous medium is replaced by a nonaqueous medium (such as tetrachloroethylene). Tetrachloroethylene can dissolve grease from materials that should not be treated by water. Since there is also polar dirt (such as sugars, minerals, etc.), a small amount of water needs to be added. This leads to the... 

Figure 15.17 Soap dissolves grease like this.

Soaps Substances formed by saponification. In this reaction, the oil or fat (glyceryl ester) is hydrolysed by aqueous sodium hydroxide to produce the sodium salt of the fatty acid, particularly sodium stearate (from stearic acid). Soap will dissolve grease because of the dual nature of the soap molecule. It has a hydrophobic part (the hydrocarbon chain) and a hydrophilic part (the ionic head) and so will involve itself with both grease and water molecules. However, it forms a scum with hard water by reacting with the Ca2+ (or Mg2+) present. 

Cleaners that contain strong bases are the most effective for dissolving grease and grime. Bases are effective because they produce soaps when they react with the fatty acids in grease. When a strong base (such as sodium hydroxide, NaOH, or potassium hydroxide, KOH) is used on a dirty oven, the fat molecules that make up the grease are split into smaller molecules. Anions from the base then bond with some of these molecules to form soap. 

How does soap dissolve grease and oil Water alone cannot dissolve dirt, which is composed largely of nonpolar hydrocarbons. When soap is mixed with water, however, the nonpolar hydrocarbon tails dissolve the dirt in the interior of the micelle. The polar head of the soap remains on the surface of the micelle to interact with water. The nonpolar tails of the soap molecules are so well sealed off from the water by the polar head groups that the micelles are water soluble. 

Soap is prepared by the basic hydrolysis or saponification of a triacylglycerol. Heating an animal fat or vegetable oil with aqueous base hydrolyzes the three esters to form glycerol and sodium salts of three fatty acids. These carboxylate salts are soaps, which clean away dirt because of their two structurally different regions. The nonpolar tail dissolves grease and oil and... 

Recognizing Cause and Effect Explain why alkanes such as hexane and cyclohexane are effective at dissolving grease, whereas water is not. 

Carbon tetrachloride is commonly used for dissolving grease from auto parts. J ust enough is used to dissolve the igniter and it is then evaporated off in a well ventilated area as the fumes are harmful. 

Disinfectant la carbona Dissolves grease Sugar mill... 

Dry cleaning, on the other hand, does not involve water. The solvents that are used in dry cleaning dissolve grease to form true solutions. 

Explain how water cannot dissolve grease, and why soap in water dissolves grease. 

The phrase like dissolves like means that polar solvents dissolve polar solutes, and nonpolar solvents dissolve nonpolar solutes. Soap is dissolved in water (a polar molecule) to dissolve grease (nonpolar). 

Unspecific irritations of skin and mucosa membrane structures can be caused by solvents. Various solvents are significant occupational irritants, e.g., solvents which cause irritant contact dermatitis."" Intact skin structures can be destroyed by solvents which dissolve grease and fat. Typically, the dermatitis is characterized by dryness, scaling and fissuring and is usually located on the hands. It is often caused by handling solvent-contaminated products or by cleaning procedures." ""... 

Most multipurpose cleaners are composed of some surfactant and disinfectant. Ammonia is commonly used because of its ability to react with grease and because it leaves no residue. Pine oil, a solution of compounds called terpenes, is used for its pleasant odor, its ability to dissolve grease, and its antibacterial nature. 

Benzene Dissolves grease and other organic compounds 6500... 

Toluene Dissolves grease and other organic materials substitute for benzene, but not so toxic 2700... 

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