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NH 2 − is a stronger base than the hydroxide ion and so cannot exist in aqueous solution. The p K a value of ammonia is estimated to be approximately 34 ( c.f. water, 14 [ 3 ] [ 4 ] ). Aprotic inorganic nonaqueous solvents
Colorimetric analysis is a method of determining the concentration of a chemical element or chemical compound in a solution with the aid of a color reagent.It is applicable to both organic compounds and inorganic compounds and may be used with or without an enzymatic stage.
Complexometric titrations are particularly useful for the determination of a mixture of different metal ions in solution. An indicator capable of producing an unambiguous color change is usually used to detect the end-point of the titration. Complexometric titrations are those reactions where a simple ion is transformed into a complex ion and ...
The procedure can also be used to assist in the analysis of complex acid mixtures containing sulfuric acid where resorting to titration in non-aqueous media is not feasible. The reaction enthalpy for the formation of barium sulfate is a modest −18.8 kJ/mol. This can place a restriction on the lower limit of sulfate in a sample which can be ...
Iodometry, known as iodometric titration, is a method of volumetric chemical analysis, a redox titration where the appearance or disappearance of elementary iodine indicates the end point. Note that iodometry involves indirect titration of iodine liberated by reaction with the analyte, whereas iodimetry involves direct titration using iodine as ...
Depending on the conditions in which the titration is performed, the manganese is reduced from an oxidation of +7 to +2, +4, or +6. In most cases, permanganometry is performed in a very acidic solution in which the following electrochemical reaction occurs: [3] MnO − 4 + 8 H + + 5 e − → Mn 2+ + 4 H 2 O; E° = +1.51 V [4]
For example, aqueous perchloric acid (HClO 4), aqueous hydrochloric acid (HCl) and aqueous nitric acid (HNO 3) are all completely ionized, and are all equally strong acids. [3] Similarly, when ammonia is the solvent, the strongest acid is ammonium (NH 4 +), thus HCl and a super acid exert the same acidifying effect. The same argument applies to ...
Phenolphthalein's common use is as an indicator in acid-base titrations. It also serves as a component of universal indicator, together with methyl red, bromothymol blue, and thymol blue. [3] Phenolphthalein adopts different forms in aqueous solution depending on the pH of the solution.