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Grade 11Physical Chemistry

3.2g of pyrolusite was treated with 50ml of 0.5 M oxalic acid and some sulphuric acid. The oxalic acid left undecomposed was raised to 250ml in a flask. 25 ml of this solution when treated with 0.02M kmno4 required 32ml of the solution. find the % of mno2 in the sample and also the % of available oxygen

Profile image of Kabir Jain
7 Years agoGrade 11
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1 Answer

Profile image of Ravi Kumar
6 Years ago
Mill eq of kmno4=0.02*32*5=3.2  So eq of italic acid=3.2in 25 ml so in 250ml=32.    WT of mno2= 50-32/1000*87/2=.783(converted Mill equal to equal and 87 is mass of mno2 and nf is 2)    percentage of mno2=.783/3.2*100=24.46