A sample of 1.44 g of ferrous oxalate, FeC2O4 (Fe 56, C 12, O 16), is titrated in hot acidic solution with 0.020 M KMnO4. Both Fe^2+ and oxalate are oxidised (to Fe^3+ and CO2) and MnO4^- goes to Mn^2+. Calculate the volume of the permanganate solution needed. Give the answer in mL to the nearest integer.

JEE Advanced levelNumerical answerDifficulty 3 of 3rx063

A sample of 1.44 g of ferrous oxalate, $FeC X_{2} O X_{4}$ (Fe 56, C 12, O 16), is titrated in hot acidic solution with 0.020 M $KMnO X_{4}$ . Both $Fe X^{2 +}$ and oxalate are oxidised (to $Fe X^{3 +}$ and $CO X_{2}$ ) and $MnO X_{4} X^{-}$ goes to $Mn X^{2 +}$ . Calculate the volume of the permanganate solution needed. Give the answer in mL to the nearest integer.

Numerical answer type, answer in mL, tolerance 1.

Molar mass of

FeC X_{2} O X_{4}

= 56 + 24 + 64 = 144 g/mol, so n = 1.44/144 = 0.01 mol. The n-factor of

FeC X_{2} O X_{4}

is 1 + 2 = 3 and that of

MnO X_{4} X^{-}

is 5, so n(

MnO X_{4} X^{-}

) = 0.01 x 3/5 = 0.006 mol. Volume = 0.006/0.020 = 0.30 L = 300 mL.