1 N KMnO4 용액 1 L 제조 방법

1 N KMnO4 용액 1 L 제조 방법

 

----------------------------------------

 

▶ 산성 용액과 염기성 용액에서 KMnO4의 당량과 g 당량수

http://ywpop.tistory.com/3795

 

 

따라서

만약 KMnO4를 사용할 실험 조건이 산성이라면,

KMnO4 31.606 g을 1 L짜리 부피 플라스크에 넣고,

표시선까지 증류수를 채우면

1 N KMnO4 용액 1 L가 됩니다.

 

만약 KMnO4를 사용할 실험 조건이 염기성 또는 중성이라면,

KMnO4 52.677 g을 1 L짜리 부피 플라스크에 넣고,

표시선까지 증류수를 채우면

1 N KMnO4 용액 1 L가 됩니다.

 

----------------------------------------

 

In the case of KMnO4, equivalent weight is reaction specific.

 

When KMnO4 is used in acid medium as oxidizer, 5 electrons are gained by Mn atom.

So equivalent weight of KMnO4 in acid medium

= molar mass / no. of electrons gained in redox reaction

= 158.03 / 5 = 31.606 g

 

So for 1 N KMnO4 solution, you have to dissolve 31.606 g KMnO4 in 1 L water.

 

(Usually a little bit excess is taken, say 32.606 g, since some crystals of KMnO4 will be remained undissolved that have to be removed by filtration. So even though u r preparing 1 N KMnO4 solution by accurate weighing, it is not a primary standard and u have to standardize it against a primary std such as oxalic acid or sodium oxalate.)

 

In alkaline or neutral medium, reaction of KMnO4 is different and Mn gains 3 electrons in redox reaction.

So, for alkaline medium redox titrations, equivalent weight of KMnO4 will be

158.03 / 3 = 52.677 g

 

So for 1 N KMnO4 solution in alkaline medium redox titration, dissolve 52.677 g in 1 L water.