Antifreeze permanent

Whenever a hydrocarbon backbone has two hydroxyl radicals attached to it, it becomes a special type of alcohol known as a glycol. The simplest of the glycols, and the most important, is ethylene glycol, whose molecular formula C2H4(OH)2. The molecular formula can also be written CHjOHCHjOH and may be printed as such on some labels. Ethylene glycol is a colorless, thick liquid with a sweet taste, is toxic by ingestion and by inhalation, and among its many uses is a permanent antifreeze and coolant for automobiles. It is a combustible liquid with a flash point of 240"F. 

An antidote has been found for ethylene glycol poisonings, but it is too costly for most hospitals. Ethylene glycol is a main ingredient in automotive antifreeze and other products. Every year, at least 6,000 people fall victim to ethylene glycol poisoning, which can lead to permanent disability or death unless it is treated immediately. Traditional treatment is complicated and tricky, but the new drug fomepizole (Antizol Orphan Medical, Inc.) has been found to be a proven antidote (Leary, 1999). 

Ethylene glycol has important commercial uses. It is an excellent permanent antifreeze for automotive cooling systems because it is miscible with water in all proportions and a 50% solution freezes at —34° (—29°F). It also... 

Ethylene glycol is traditionally associated with use as permanent-type antifreeze for internal-combustion engine cooling systems. Other uses include the production of polyesters for fibers, films, and coatings, in hydraulic fluids, in the manufacture of low freezing-point explosives, glycol ethers, and deicing solutions. 

Calculate the percent compxjsition of ethylene glycol, C2Hg02, commonly used as a permanent antifreeze in cars. 

Practice Problem 15.21 Calculate the boiling-point elevation for a 0.650 m solution of ethylene glycol, C2H4(OH)2, in water. Ethylene glycol is the main constituent of permanent antifreeze. ... 

Methanol is widely available as a solvent and in paints and antifreezes, and may be consumed as a cheap substitute for ethanol. As little as 10 ml may cause permanent blindness and 30 ml may kill, through its toxic metabolites. Methanol, like ethanol, is metabolised by zero-order processes that involve the hepatic alcohol and aldehyde dehydrogenases, but whereas ethanol forms acetaldehyde and acetic acid which are partly responsible for the unpleasant effects of hangover, methanol forms formaldehyde and formic acid. Blindness may occur because aldehyde dehydrogenase present in the retina (for the interconversion of retinol and retinene) allows the local formation of formaldehyde. Acidosis is due to the formic acid, which itself enhances pH-dependent hepatic lactate production, so that lactic acidosis is added. 

Ethylene glycol, HOCH2CH2OH, is the major component of permanent antifreeze. It depresses the freezing point of water in an automobile radiator and also raises its boiling point. The solution remains in the Uquid phase over a wider temperamre range than does pure water. This protects against both freezing and boil-over. 

Many simple alcohols are important raw materials in the industrial synthesis of polymers, fibers, explosives, plastics, and pharmaceutical products. Phenols are widely used in the preparation of plastics and dyes. Solutions of phenols are used as antiseptics and disinfectants. Some uses of polyhydric alcohols depend on their relatively high boiling points. For instance, glycerine is used as a wetting agent in cosmetic preparations. Ethylene glycol (bp 197°C), which is miscible with water, is used in commercial permanent antifreeze. 

Conspicuously, different from all other polymers is the antifreeze, which at all freezing rates partitioned equally between ice and the imfrozen solution i.e., it appears to be equally "soluble" in ice and water. This result confirms that the molecule can interact with the ice phase over a kinetically long period of time. It is not known from these results whether the mechanism is a permanent adsorption this would require supporting evidence from other physical measurement techniques. All the other solutes show a rate-dependent mechanism of partitioning, presumably dominated by the diffusion rates of the molecules. LEG and FVA may exhibit some nonkinetic partitioning properties, but this has not been conclusively proven. 

The polyhydric alcohols contain more than one —OH group per molecule. Those Polyhydric alcohols are used containing two OH groups per molecule are called glycols. Important examples of poly- permanent antifreeze and in hydric alcohols include cosmetics. 

The U.S. production of methanol is 1.4 billion gallons per year. Most of It Is used to produce formaldehyde and other chemicals, but some Is used as a solvent and as an antifreeze. Methanol Is highly toxic and can cause permanent blindness because when taken Internally, It Is oxidized to formaldehyde (CH2=0), which binds to opsin, preventing formation of rhodopsin, the light-sensitive pigment needed for vision (see A Word About.. . The Chemistry of Vision, pages 76-77). 

It takes as little as 5 mL (1 tsp) of methanol to cause permanent blindness or death and unlike ethanol, methanol can be absorbed in toxic amounts by ingestion, inhalation of vapor, or absorption through the skin. Nevertheless, methanol is present in a number of common household products including antifreeze, windshield-washing fluid, and paint remover. 

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