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In neutral solution, permanganate slowly reduces to manganese dioxide (MnO 2). This is the material that stains one's skin when handling KMnO 4. KMnO 4 reduces in alkaline solution to give green K 2 MnO 4: [75] 4 KMnO 4 + 4 KOH → 4 K 2 MnO 4 + O 2 + 2 H 2 O. This reaction illustrates the relatively rare role of hydroxide as a reducing agent.
Dilution is the process of decreasing the concentration of a solute in a solution, usually simply by mixing with more solvent like adding more water to the solution. To dilute a solution means to add more solvent without the addition of more solute. The resulting solution is thoroughly mixed so as to ensure that all parts of the solution are ...
This reaction illustrates the relatively rare role of hydroxide as a reducing agent. The concentration of K 2 MnO 4 in such solutions can be checked by measuring their absorbance at 610 nm. The one-electron reduction of permanganate to manganate can also be effected using iodide as the reducing agent: 2 KMnO 4 + 2 KI → 2 K 2 MnO 4 + I 2
The term molality is formed in analogy to molarity which is the molar concentration of a solution. The earliest known use of the intensive property molality and of its adjectival unit, the now-deprecated molal, appears to have been published by G. N. Lewis and M. Randall in the 1923 publication of Thermodynamics and the Free Energies of Chemical Substances. [3]
In a strongly basic or alkaline solution, permanganate(VII) is reduced to the green manganate ion, MnO 2− 4 with an oxidation state of +6. MnO − 4 + e − → MnO 2− 4. In a neutral solution, however, it gets reduced to the brown manganese dioxide MnO 2 with an oxidation state of +4. 2 H 2 O + MnO − 4 + 3 e − → MnO 2 + 4 OH −
It is necessary to calculate the mass of a solid acid which will react with about 20 cm 3 of this solution (for a titration using a 25 cm 3 burette): suitable solid acids include oxalic acid dihydrate, potassium hydrogen phthalate and potassium hydrogen iodate. The equivalent weights of the three acids 63.04 g, 204.23 g and 389.92 g ...
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M is the molar mass of the solvent. T b is boiling point of the pure solvent in kelvin. ΔH vap is the molar enthalpy of vaporization of the solvent. Through the procedure called ebullioscopy, a known constant can be used to calculate an unknown molar mass. The term ebullioscopy means "boiling measurement" in Latin.