1.6 g of pyrolusite ore was treted with 50 " mL of " 1.0 N oxalic acid and some sulphuric acid. The oxalic acid left undecomposed was raised to 250 mL in a flask. 25 " mL of " this solution, when titrated with 0.1 N `KMnO_4` required 32 " mL of " this solution. Find out the percentage of pure `MnO_2` and also the percentage of available oxygen from `MnO_2`.

1.6 g of pyrolusite ore was treted with 50 " mL of " 1.0 N oxalic acid

1.	1.6 g of pyrolusite ore was treted with 50 " mL of " 1.0 N oxalic acid and some sulphuric acid. The oxalic acid left undecomposed was raised to 250 mL in a flask. 25 " mL of " this solution, when titrated with 0.1 N `KMnO_4` required 32 " mL of " this solution. Find out the percentage of pure `MnO_2` and also the percentage of available oxygen from `MnO_2`.
Answer» Meq.of `MnO_(2)=` Meq.of oxalic acid added-Meq.of oxalic acid left `=1xx50-0.1xx32xx10=18 ("in" 250 mL)` `( :. E=(86.9)/(2))` or `:. (w)/(E )xx1000=18` or `w_(MnO_(2))=(18xx86.9)/(2xx1000)=0.7821g` `:. % "of" MnO_(2)=(0.7821)/(1.6)xx100=48.88%` Also Meq.of `MnO_(2)="Meq.of" O_(2)=18` `:. (w)/(8)xx1000=18` `w_(O_(2))=0.144g` `:. %` of available `O_(2)=(0.144)/(1.6)xx100=9%`

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