why after added KMnO4 change colored and after that change color KMno4? in Determination of Chloride Ion Concentration by Titration (Volhard’s Method) by using cheese
This is a chemistry question but it is so garbled I have no idea how to respond. It appears to have two mixed questions. The Volhard method has nothing to do with KMnO4.
In the determination of chloride ion concentration using the Volhard's method, potassium permanganate (KMnO4) is used as an indicator. KMnO4 is initially added to the solution containing the chloride ions and reacts with them to form a reddish-brown precipitate called manganese(IV) oxide (MnO2). This process occurs because chloride ions (Cl-) oxidize manganese(IV) ions (MnO4-) to manganese(IV) oxide.
The appearance of the reddish-brown precipitate indicates that all the chloride ions have reacted with the KMnO4. At this point, the mixture is saturated with manganese(IV) oxide, which masks the color change.
To observe the color change and determine the endpoint of the titration accurately, an excess of iron(II) ions (Fe2+) is added to the solution. The excess Fe2+ reacts with the remaining KMnO4, converting it to iron(III) ions (Fe3+). Once all the excess KMnO4 is consumed, the color of Fe3+ ions changes in solution.
The appearance of a permanent pale pink color in the solution indicates that all the chloride ions have been titrated with KMnO4, and the endpoint has been reached.
So, in summary, KMnO4 changes color initially due to the formation of manganese(IV) oxide, but it is the change in the color of Fe3+ ions that confirms the endpoint and determines the chloride ion concentration accurately.