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The first and faster [citation needed] process is the removal of hydrogen and oxygen as units of water by the concentrated sulfuric acid. This occurs because hydration of concentrated sulfuric acid is strongly thermodynamically favorable, with a standard enthalpy of reaction of −880 kJ/mol.
The oleum is then diluted with water to form concentrated sulfuric acid. H 2 SO 4 + SO 3 → H 2 S 2 O 7 H 2 S 2 O 7 + H 2 O → 2 H 2 SO 4. Directly dissolving SO 3 in water, called the "wet sulfuric acid process", is rarely practiced because the reaction is extremely exothermic, resulting in a hot aerosol of sulfuric acid that requires ...
The Piria reaction. In the Tyrer sulfonation process (1917), [7] at some time of technological importance, benzene vapor is led through a vessel containing 90% sulfuric acid the temperature of which is increased from 100 to 180°C. Water and benzene are continuously removed and the benzene fed back to the vessel. In this way an 80% yield is ...
The conversion of ethanol to ethylene is a fundamental example: [3] [4] CH 3 CH 2 OH → H 2 C=CH 2 + H 2 O. The reaction is accelerated by acid catalysts such as sulfuric acid and certain zeolites. These reactions often proceed via carbocation intermediates as shown for the dehydration of cyclohexanol. [5] Some alcohols are prone to dehydration.
Notable examples include alkali metals, lithium through caesium, and alkaline earth metals, magnesium through barium. Some water-reactive substances are also pyrophoric, like organometallics and sulfuric acid. The use of acid-resistant gloves and face shield is recommended for safe handling; fume hoods are another effective control of such ...
The Bunsen reaction is a chemical reaction that describes water, sulfur dioxide, and iodine reacting to form sulfuric acid and hydrogen iodide: 2H 2 O + SO 2 + I 2 → H 2 SO 4 + 2HI This reaction is the first step in the sulfur-iodine cycle to produce hydrogen .
Treatment of sulfur with hydrogen gives hydrogen sulfide.When dissolved in water, hydrogen sulfide is mildly acidic: [5] H 2 S ⇌ HS − + H +. Hydrogen sulfide gas and the hydrosulfide anion are extremely toxic to mammals, due to their inhibition of the oxygen-carrying capacity of hemoglobin and certain cytochromes in a manner analogous to cyanide and azide.
The contact process is a method of producing sulfuric acid in the high concentrations needed for industrial processes. Platinum was originally used as the catalyst for this reaction; however, because it is susceptible to reacting with arsenic impurities in the sulfur feedstock, vanadium(V) oxide (V 2 O 5) has since been preferred.