Diazotization Titration or Nitrite Titration Diazotization is used in the analysis of aromatic compounds containing an amino group in the molecules. This analysis . View Notes – from ECH at University of Florida. Diazotization titration (Nitrite Titration) Mr. V. M. Patil Assistant Professor & PG. 20 Nov DIAZOTIZATION – authorSTREAM Presentation. CONDITION FOR DIAZOTIZATION RATE OF TITRATION Different amino compound react.
|Published (Last):||28 September 2009|
|PDF File Size:||20.11 Mb|
|ePub File Size:||12.9 Mb|
|Price:||Free* [*Free Regsitration Required]|
Retrieved 28 September The liberated iodine is back titrated with the sodium thiosulphate using starch as the external indicator. Then the solution is titrated with the sodium nitrite solution until the starch iodide paper turns into blue colour.
The obtained nitrous acid is reacted with the primary aromatic amine to form the diazonium salt. The diazonium salt is added together with potassium carbonateand after grinding hitration mixture at room temperature the surface of the nanotubes are covered with chlorophenyl groups with an efficiency of 1 in 44 carbon atoms.
Pharmaceutical Analysis by P. D. Chaithanya Sudha
It is also used in the preparation of hydrocarbonsaryl halidearyl cyanideand aryl diazotizwtion It is used in the assay of sulpha drugs like dapsonesulphonamides It is diazotizatjon used in the assay of various drugs like benzocaineprocainamideprocainesuraminsodium amino salicylate.
Organic compounds Carbon-heteroatom bond forming reactions Functional groups Organonitrogen compounds. Thus the electrode will act as if it were an electrode of metallic hydrogen. Hudson, and James M.
May be used for the analysis of drugs such as benzocaine, dapsone, primaquine etc. Lowitz first prepared the moisture-free solvents non-aqueous solvents. For example, treatment of benzenediazonium chloride with benzene an aromatic compound in the presence of sodium hydroxide gives diphenyl:. Then concentrated hydrochloric acid and potassium bromide are added and the rest of the volume is filled with the distilled water. An electron is transferred from the silicon surface to the diazonium salt in an open circuit potential reduction leaving a silicon radical cation diaztoization a diazonium radical.
The resulting azo compounds are often useful dyes and in fact are called azo dyes. The general procedure is followed by weighing diaztization sample and transferring it into the standard flask.
PRINCIPLE The principle involved in this method is that the primary aromatic amine present in the sample reacts with the sodium nitrite in the presence of acid such as hydrochloric acid to obtain a diazonium salt. Diazotization Titrations free pharmacy study material pharmaceutical analysis pharmaceutical analysis lecture notes. Hence the non-aqueous titrimetric method is used.
A similar conversion is also achieved by treating benzenediazonium chloride with ethanol and copper powder. The most widely practiced reaction of diazonium salts is azo coupling.
Optimum temperature for most amine is 0 C, when they form relatively stable diazo compounds. Arenediazonium cations undergo several reactions in which the N 2 group is replaced by another group or ion.
Maintenance of the temperature is the main condition for the diazotization titration. The amine reacts with the nitrous acid to form nitrosamine, which is followed by the tautomerisation and the water molecule is lost to form the diazonium ion.
The percentage amount of the sulpha drug is determined by the following equation: Diazonium salts can be converted to thiols in a two-step procedure.
The main principle involved in this method is to treat the amino group containing drug with the acid solution. An acid-base indicator e.
Chapter 3 Chemical reactions. In order to view it, please contact the author of the presentation. Classified as solid state, diazotizayion, liquid ion exchanger and glass type.
Rejuvenation required over a period of time to avoid any errors. The main principle involved in this method is riazotization formation of the diazo oxide which is more stable than the diazo compounds. In the Gatterman reaction, benzenediazonium chloride is warmed with copper powder and HCl or HBr to produce chlorobenzene and bromobenzene respectively. For example, the aminophenol is readily oxidized by the nitrous acid and converted to the quinones in the presence of copper sulphate solution yitration forms the diazo oxide compounds.
Conversion of Diazonium Salt to Phenol. Benzenediazonium chloride reacts with compounds containing activated double bonds to produces phenylated products. This reaction goes by the German name Phenolverkochung “cooking down to yield phenols”. Sulphanilic acid and anthranilic acid. This allows the pH of the solution to be measured throughout the titration.
In some reactions, the solution changes colour without any added indicator. When sodium nitrite is reacted with the hydrochloric acid sodium chloride and nitrous acid are formed. The end point is determined by the above-mentioned methods. In non-aqueous titrations, usually, the milli volt scale of potentiometer is used rather than pH scale since the potential of the non-aqueous systems exceed the pH scale.
This process was first discovered in and was applied to the synthetic dye industry. After the end point, addition of further ions does not affect the concentration of the complex so that the titration curve has almost horizontal portion after the equivalence point.
A more common process uses a paper coated with diazo, coupler and an acid to inhibit coupling; after exposure the image is developed by a vapor mixture of ammonia and water which forces coupling. An in silico study diqzotization demonstrates that in the period 4 elements from titanium to copper the binding energy decreases from left to right because the number of d-electrons increases.
So far grafting of diazonium salts on metals has been accomplished on ironcobaltnickelplatinumpalladiumzinccopper and gold surfaces.