Calculate the percentage amount of oxalate in a given sample of oxalate salt when `0.3` g of salt was dissolved in 100 mL and 10 mL of which required 8 mL of `N/20 KMnO_(4)` solution .

Explanation

Let the amount of oxalate in the sample be x g .
Now ,
m.e of `KMnO_(4) = 1/20 xx 8 = 0.4 " " ` …(Eqn.1)
` :. ` m.e of 10 mL of oxalate salt solution = 0.4 ..(Eqn.2)
` :. ` m.e of 100 mL of oxalate solution = 4.0
but m.e of oxalate = m.e of oxalate salt = 4 ...(Eqn . 7)
` :. ` equivalent of oxalate = `4/1000 = (0.04) ` ....(Eqn.3)
Wt . of oxalate ` = (0.004 xx 44 ) g `
` = 0.176 g`
` {" eq. wt of " C_(2)O_(4)^(2-)= 88/2 = 44}`
Percentage amount of oxalate = `(0.176 )/(0.3) xx 100 = 58.67 ` %