One of the practical disadvantages of this reaction is stain formation in glassware surfaces as the result of oxidation of KMnO4 to MnO2. Any chemical reaction dissolving the MnO2 can clean these stains. Find and propose a method to remove these stains. Write the balanced equation for the reaction of your choice

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol