question: why does rubbing alcohol melt ice?
comment: Water freezes at 0°C, alcohol doesn't, it freezes at lower temperatures. Ice = water. Water + alcohol = alcohol, therefore the freezing temperature changes to lower than 0°C, melting ice.
passages: The term "rubbing alcohol" came into prominence in North America in the mid-1920s. The "original" rubbing alcohol was literally used as a liniment for massage; hence the name. This original rubbing alcohol was rather different from today's precisely formulated surgical spirit; in some formulations it was perfumed and included different additives, notably a higher concentration of methyl salicylate.
  
  The name "rubbing" also emphasized that the alcohol was not intended for consumption, a significant distinction in Prohibition-era America; nonetheless it had become a well-documented surrogate alcohol as early as 1925.
  
  Section::::Properties.
   One of the most famous stories is that he used to rub liquor into his hair. He would drink his cognac or whisky, leaving a small amount to pour into his hand, and rub it into his hair; saying "A liddle insida, a liddle outsida. Bon! She maka da hair grow!"
   One generic process of icing beer involves lowering the temperature of a batch of beer until ice crystals form. Since alcohol has a much lower freezing point (-114 °C; -173.2 °F) than water and doesn't form crystals, when the ice is filtered off. This creates a concoction with a higher volume ratio of alcohol to water and therefore creating a beer with a higher alcohol content by volume. The process is known as "fractional freezing" or "freeze distillation".
   In January 2001, Ice was arrested by police in Davie, Florida, for assaulting his wife, Laura. According to the criminal complaint, Ice and his wife argued as they drove on Interstate 595. Ice admitted to pulling hair from her head to prevent her from jumping out of the truck's window. He pleaded guilty to charges of disorderly conduct four months later and was sentenced to probation and ordered to attend family therapy sessions.
   Icy drink mixtures with rum, first identified as swizzles and later as Rum Swizzles, have been mentioned in literature in a variety of locations since the mid 18th century: Fort Ticonderoga, New York (1760), the Caribbean island of Saint Kitts (1838), Bridgetown, Barbados (1841), Great Britain (1862), Bridgeport, Barbados (1908), and the island of Saint Thomas in the U.S. Virgin Islands (1911). In these earliest versions, the drink typically consisted of one part of rum diluted with five or six parts water (sometimes with additional aromatic ingredients), which was mixed by rotating between the palms of the hands a special forked stick made from a root; another account describes it as spruce beer with added rum and sugar.
   BULLET::::- even if temperatures "somewhat below" the freezing point of ethyl alcohol are achieved, there will still be alcohol and water mixed as a liquid, and
  
  BULLET::::- at some still lower temperature, the remaining alcohol-and-water solution will freeze without an alcohol-poor solid being separable.
  
  The best-known freeze-distilled beverages are applejack and ice beer. Ice wine is the result of a similar process, but in this case, the freezing happens "before" the fermentation, and thus it is sugar, not alcohol, that gets concentrated. For an in-depth discussion of the physics and chemistry, see eutectic point.
  
  Section::::Purification of solids.
   It is also dangerous to ships owing to the increase in weight when ice forms on the superstructure. It may destabilise a vessel and cause it to overturn, especially in rough seas.
  
  Section::::Examples of damage.
  
  In February 1994, a severe ice storm caused over $1 billion in damage in the Southern United States, primarily in Mississippi, Tennessee, and Alabama. One particularly severe ice storm struck eastern Canada and northern parts of New York and New England in the North American ice storm of 1998.
   "Bowuzhi" Chapter 6 has two consecutive items describing highly potent liquors, possibly the first references to "freeze distillation" or technically fractional freezing (Needham et al. 1980: 151). This technique for concentrating alcohol involves repeatedly freezing wine or beer and removing the ice (for instance, applejack or "ice beer", but not ice wine made from frozen grapes). The earliest Chinese record is traditionally believed to be the (late 7th century) "Liang Sigong ji" 梁四公記 "Tales of the Four Lords of Liang", which says emissaries from Gaochang presented "dòngjiǔ" 凍酒 "frozen-out wine" to Emperor Wu of Liang around 520.
   In the second step, the nucleophilic water molecule attacks the more substituted carbon, liberating the electrons participating in its bond with mercury. The electrons collapse to the mercury ion and neutralizes it. The oxygen in the water molecule now bears a positive charge.
  
  In the third step, the negatively charged acetoxy ion that was expelled in the first step attacks a hydrogen of the water group, forming the waste product HOAc. The two electrons participating in the bond between oxygen and the attacked hydrogen collapse into the oxygen, neutralizing its charge and creating the final alcohol product.
  
  Section::::Regioselectivity and stereochemistry.
   In this process, a mixture of dextrin and alcohol is subjected to simultaneous spraying and heating. The spraying converts the liquid to small drops (up to several hundred µm (micrometers) in diameter), and the heat causes the hydrous dextrin to form a film. When the film dries, the drop becomes a microcapsule containing alcohol and dextrin.
  
  Before and after drying, comparing the amounts of water and alcohol, about 90% of water is removed and about 10% of ethyl alcohol is lost. One of the reasons which are considered, is the following.
   "The Routledge Dictionary of Modern American Slang and Unconventional English" defines Ice luge as "a block of ice used in a drinking game in which a shot of vodka, tequila, or other alcoholic drink is poured down the ice into the drinker's mouth."
  
  Section::::Composition and production.
   The drink gets its name from the way it is commonly consumed; the usual procedure is to leave about a fifth of the glass empty to allow the drink to fizz, then to hold one's hand over the top of the glass and then slam it onto a hard surface to mix it. The slamming action releases gas bubbles from the mixed drink causing it to foam vigorously. It will then quickly escape the glass if not imbibed immediately, the result (and intention) of which is swift intoxication.
   Irish moss is commonly used as a clarifying agent or finings in the process of brewing (beer), particularly in homebrewing. A small amount is added to the kettle or "copper", where it is boiled with the wort, attracting proteins and other solids, which are then removed from the mixture after cooling along with the copper finings.
  
  Section::::Life history.
   Developed by brewing a strong, dark lager, then freezing the beer and removing some of the ice. This would concentrate the aroma and taste of the beer, and also raise the alcoholic strength of the finished beer. More specifically, the method is as follows. "By cooling beer to just below freezing, you separate out a large portion of water from the alcohol, which has a lower freezing point. You then skim off the ice crystals from the brew leaving behind a beer that is twice as potent as the original." That produces a beer with 12 to 15 per cent alcohol. In North America, water would be added to lower the alcohol level.
   Section::::Characters.:Yu Guo (Xu Dai).
   Following the success of "Ice Ice Baby", record producer Suge Knight and two bodyguards arrived at The Palm in West Hollywood, where Ice was eating. After shoving Ice's bodyguards aside, Knight and his own bodyguards sat down in front of Ice, staring at him before finally asking "How you doin'?" Similar incidents were repeated on several occasions. Eventually, Knight showed up at Ice's hotel suite on the fifteenth floor of the Bel Age Hotel, accompanied by a member of the Los Angeles Raiders football team. According to Ice, Knight took him out on the balcony by himself, and implied that he would throw him off the balcony unless he signed the publishing rights to the song over to Knight; Knight used Ice's money to help fund Death Row Records.
   Section::::History.
   Glaze from freezing rain on a large scale causes effects on plants that can be severe, as they cannot support the weight of the ice. Trees may snap as they are dormant and fragile during winter weather. Pine trees are also victims of ice storms as their needles will catch the ice, but not be able to support the weight. Orchardists spray water onto budding fruit to simulate glaze as the ice insulates the buds from even lower temperatures. This saves the crop from severe frost damage.
   Section::::Control.
  
  There are several ways to control frazil ice build up. They include suppression, mechanical control, thermal control, vibration, materials selection and damage mitigation.
  
  Section::::Control.:Suppression.
   The United States Pharmacopeia defines 'isopropyl rubbing alcohol USP' as containing approximately 70 % alcohol by volume (≈ 95º alcohol proof) of pure isopropyl alcohol and
  
  defines 'rubbing alcohol USP' as containing approximately 70 percent by volume of denatured alcohol. In Ireland and the UK, the comparable preparation is surgical spirit B.P., which the British Pharmacopoeia defines as 95% methylated spirit, 2.5% castor oil, 2% diethyl phthalate, and 0.5% methyl salicylate.
   BULLET::::9. The pint glass is removed and 2-3 ice cubes are placed into it. The opening of the pint glass is immediately sealed with the palm of the bartender's hand.
  
  BULLET::::10. The pint glass is shaken: this has the effect of cooling the alcohol vapors and causing them to condense on the ice cubes, the walls of the glass and the air inside the glass.
   Nat X was cruel to all of his guests, "greeting" nearly all of them with, "Sit yo' ass down!" Perhaps the most memorable episode featured host Kevin Bacon as Vanilla Ice. Nat told Ice that he could not dance, and even persuaded his other guest, Colin Powell, to dance with him in order to show Ice how to do it.
   Under its alternative name of "wintergreen oil", methyl salicylate is a common additive to North American rubbing alcohol products. Individual manufacturers are permitted to use their own formulation standards in which the ethanol content for retail bottles of rubbing alcohol is labeled as and ranges from 70-99% v/v.
  
  All rubbing alcohols are unsafe for human consumption: isopropyl rubbing alcohols do not contain the ethyl alcohol of alcoholic beverages; ethyl rubbing alcohols are based on denatured alcohol, which is a combination of ethyl alcohol and one or more bitter poisons that make the substance toxic.
  
  Section::::History.
   The most common use of a frigorific mixture is to melt ice. When ammonium chloride salt is placed on ice when the ambient temperature is greater than −17.8 °C (0 °F), the salt melts some of the ice and the temperature drops to −17.8 °C. Since the mixture is colder than the ambient temperature, heat is absorbed and the temperature rises. This causes the salt to melt more of the ice to drive the temperature down again. The process continues until all of the salt is dissolved in the melted ice. If there is enough salt present, then all of the ice will be melted.
   BULLET::::11. Preparation is now complete. The drinker first downs the shot or drinks it through a straw. Then the straw is slipped through the bartender's fingers into the pint glass, whereby the drinker "drinks" the condensed alcohol - actually mainly inhaling the alcohol vapors inside the glass. Finally, the drinker uses the straw to suck up the spirits which have collected in the saucer. The combination of ingested and inhaled alcohol makes this drink extremely potent. The ice cubes (and the layer of condensed alcohol on them) may be eaten if desired.
  
  Section::::Backdraft physics.
  