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The carbon snake is a demonstration of the dehydration reaction of sugar by concentrated sulfuric acid. With concentrated sulfuric acid, granulated table sugar ( sucrose ) performs a degradation reaction which changes its form to a black solid-liquid mixture . [ 1 ]
The classic example of a dehydration reaction is the Fischer esterification, which involves treating a carboxylic acid with an alcohol to give an ester RCO 2 H + R′OH ⇌ RCO 2 R′ + H 2 O. Often such reactions require the presence of a dehydrating agent, i.e. a substance that reacts with water.
A vacuum desiccator (left) and desiccator (right). Silica gel with cobalt chloride indicator placed in the lower shelf is used as the desiccant.. A desiccator is a heavy glass or plastic container, now somewhat antiquated, used in practical chemistry for drying or keeping small amounts of materials very dry.
During the chemical reaction two sterols bind together and bisterol (bisteroid) is formed; bi-cholestadien (double cholestene with two double bonds) in a case of cholesterol. Red colour of a solution is a consequence of bi- sulfonic acid of a bi-cholestadien, which is a product of sulfuric acid sulfonating bi-cholestadien.
In physiology, dehydration is a lack of total body water that disrupts metabolic processes. [3] It occurs when free water loss exceeds free water intake. This is usually due to excessive sweating, disease, or a lack of access to water. Mild dehydration can also be caused by immersion diuresis, which may increase risk of decompression sickness ...
Molisch test (using α-napthol) indicating a positive result (see purple ring). Molisch's test is a sensitive chemical test, named after Austrian botanist Hans Molisch, for the presence of carbohydrates, based on the dehydration of the carbohydrate by sulfuric acid or hydrochloric acid to produce an aldehyde, which condenses with two molecules of a phenol (usually α-naphthol, though other ...
If drying is continued, the slope of the curve, the drying rate, becomes less steep (falling rate period) and eventually tends to become nearly horizontal at very long times. The product moisture content is then constant at the "equilibrium moisture content", where it is, in practice, in equilibrium with the dehydrating medium. In the falling ...
Dehydration of primary alcohols does not work well. The reagent is soluble in common organic solvents and alcohol dehydration takes place with syn elimination through an intramolecular elimination reaction. The Burgess reagent is a carbamate and an inner salt. A general mechanism is shown below.