What is the function of pyridine in the formation of sulfonamide and why is the anhydrous form used?
604373
In the preparation of Sulfonamide, pyridine acts as a base and is an important player in the mechanism. The anhydrous form is used because the presence of water decreases reaction yield.
1075772
the covalent reaction it undergoes is a dehydration reaction
75373
A previous answerer almost got it right.  Many drugs are practically insoluble in water, yet they are basic.  Such drugs, being bases, can react with acids to form salts.  These salts, if properly chosen, can be quite water soluble.  Very commonly, salts formed by reacting bases with hydrogen chloride or hydrochloric acid (HCl) are quite water soluble.  It is often important to have good water solubility in a drug to aid its dissolution in the stomach or to make it appropriate for percutaneous (injection, intravenous, etc.) use.  These hydrochloride salts are designated by listing "HCl" after the drug name.
468805
in water: a molecule of water will hyrdoyse the iron ion creating an iron hydroxide ion and a hydronium ion.  If the water is evaporate you still have the same compound except with some water trapped in the crystal structure.\n\nin ammonia: a co ordination complex is formed using 6 ammonia ligands [Fe(NH3)6]NO2\n\nAnd i don't actually know what would happen in hyrochloric acid
654500
Many of them oxidize H2S\n\nso its like water but using sulphur, thats why a lot of these bacteria are purple. \n\nheres an abstract on how they work, or at least will give you a general idea ans some examples!\n\nSeven strains of heterotrophic iron-oxidizing acidophilic bacteria were examined to determine their abilities to promote oxidative dissolution of pyrite (FeS2) when they were grown in pure cultures and in mixed cultures with sulfur-oxidizing Thiobacillus spp. Only one of the isolates (strain T-24) oxidized pyrite when it was grown in pyrite-basal salts medium. However, when pyrite-containing cultures were supplemented with 0.02% (wt/vol) yeast extract, most of the isolates oxidized pyrite, and one (strain T-24) promoted rates of mineral dissolution similar to the rates observed with the iron-oxidizing autotroph Thiobacillus ferrooxidans. Pyrite oxidation by another isolate (strain T-21) occurred in cultures containing between 0.005 and 0.05% (wt/vol) yeast extract but was completely inhibited in cultures containing 0.5% yeast extract. Ferrous iron was also needed for mineral dissolution by the iron-oxidizing heterotrophs, indicating that these organisms oxidize pyrite via the "indirect" mechanism. Mixed cultures of three isolates (strains T-21, T-23, and T-24) and the sulfur-oxidizing autotroph Thiobacillus thiooxidans promoted pyrite dissolution; since neither strains T-21 and T-23 nor T. thiooxidans could oxidize this mineral in yeast extract-free media, this was a novel example of bacterial synergism. Mixed cultures of strains T-21 and T-23 and the sulfur-oxidizing mixotroph Thiobacillus acidophilus also oxidized pyrite but to a lesser extent than did mixed cultures containing T. thiooxidans. Pyrite leaching by strain T-23 grown in an organic compound-rich medium and incubated either shaken or unshaken was also assessed. The potential environmental significance of iron-oxidizing heterotrophs in accelerating pyrite oxidation is discussed.
425237
Sulfanilamide is the active bulk part of protonsil (a pro-drug)and PROTONSIL is reduced to sulfanilamide in vivo by by the breakage of N=N bond and then sulfanilamide competitively inhibits an enzyme that is required for DNA synthesis. To cut a long story short; there is PROTONSIL reduction NOT SULFANILAMIDE reduction in vivo.
1151718
You can perform electrolysis of water (or electrolysis of dilute sulphuric acid as it is called). The apparatus used is a Hoffman's voltmeter, with platinum electrodes. On passing an electric current, H+ and OH- ions in the water molecule dissociate and migrate to the corresponding electrodes.\n\nAt cathode: H+  + e- --------> H(g)\nH(g) + H(g) --------> H2(g)\n\n2 volumes of hydrogen are released at cathode.\n\nAt anode: OH- (aq) -----------> OH(g) + e-\nOH(g) + OH(g) -----------> H2O + O(g)\nO(g) + O(g) -------------> O2(g)\n\n1 volume of oxygen released at anode\nThus hydrogen and oxygen are released at a ratio of 2:1
899857
A solid that is formed by a chemical reaction.
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pervious answer is incorrent.\n\nThere are 0.1 moles of H30+ ions in the solution as once sulphuric acid has dissociated once it creates the rather stable conjugate base HSO4+ which is what makes sulphuric acid "strong".  This ion has a very small pK value, and is to all purposes not dissociated.  Reaction of the solution with a base will encourage it to dissociate tho.
203222
It's a carbon-hydrogen chain. \nIt is used in organic reactions.
1048196
A rotating ring (Pt)-disc (FeS2) electrode was used to investigate the surface oxidation process of pyrite in the hydrochloric solutions. It is reported for the first time that the oxidation intermediates of pyrite were formed on the disc electrode and then oxidized on the ring electrode. The results indicate that at a rotation rate of 20 Hz, when the disc electrode potential was in the region of 0.43 to 0.62 V and the ring electrode potential was at 1 V vs a standard calomel electrode (SCE), approximately 50% of the reacted pyrite was oxidized to ferric and sulfate ions and the other 50% was oxidized to sulfur and ferrous ions on the disc electrode. The latter was further oxidized to ferric ions on the ring electrode. As the disc electrode potential increased to 1.22 V vs SCE, more than 90% of the reacted pyrite was oxidized to ferric and sulfate ions on the disc electrode and less than 10% formed ferrous ions, which were further oxidized to ferric ions on the ring electrode.
106054
Hydrochloride\n\nFrom our old friend the Wikipedia:\n\nConverting otherwise insoluble amines into their hydrochlorides is a common way to make them water and acid-soluble. This is particularly desirable for substances used in medications. Many pharmaceutical substances used are prepared as hydrochlorides so that they may be quickly absorbed in the gastrointestinal tract.
979145
During acid hydrolosis, it is in fact a water molecule which gets attached to the alkene, forming an alcohol.\n\nThe H+ from the acid attacks the pi bond of the alkene.  This is because the H+ is an electrophile and attacks the high electron density of the pi bond.\n\nAs the H+ binds to the alkene, the pi bond is broken and an intermediate carbocation is formed.  An OH- from the water will quickly bind to the carbocation, forming the alcohol.\n\nThis reaction is an example of an electrophilic addition reaction.
449522
http://en.wikipedia.org/wiki/Sulphuric_acid
215160
http://www-ec.njit.edu/~skawinsk/chem243/chap11/chap11.htm\nthis may help–near the bottom
983710
H2SO4 will dehydrate and remove water.\n\n\n(CH3)2 CH - CH2-CH=CH-(CH3)2
997096
Without consulting any reaction energy tables, my money's on HNO3.  Nitric acid is one of about a half dozen really strong acids and will give off a tremendous amount of heat when dissolved in water.  I don't think any of these will actually react with water, but nitric acid will certainly dissolve the most violently.  If you have access to reference tables, you'll want to look up reaction enthalpies, or dissolution enthalpies.  \n\nOf the compounds you listed, Ammonia (NH3) is a weak base that will not do anything special when added to water, Nitric Acid (HNO3) is a very strong mineral acid that dissolves exothermically, Sodium Sulfide (Na2S) is an ionic salt that should dissolve without any fireworks, and Hydrogen Cyanide (HCN) is a somewhat weaker acid that I would expect to give off less heat than HNO3 when dissolved in water.