To measure the quantity of MnCl 2 dissolved in an aqueous solution, it was completely converted to KMnO 4 using the reaction, MnCl 2 + K 2 S 2 O 8 + H 2 O → KMnO 4 + H 2 SO 4 + HCl (equation not balanced). Few drops of concentrated HCl were added to this solution and gently warmed. Further,…

Question

To measure the quantity of MnCl 2 dissolved in an aqueous solution, it was completely converted to KMnO 4 using the reaction, MnCl 2 + K 2 S 2 O 8 + H 2 O &#8594; KMnO 4 + H 2 SO 4 + HCl (equation not balanced). Few drops of concentrated HCl were added to this solution and gently warmed. Further, oxalic acid 225 &#160; mg ) was added in portions till the colour of the permanganate ion disappeared. What is the quantity of MnCl 2 (in mg) present in the initial solution? (Atomic weights in g &#160; mol - 1 : &#160; Mn = 55 , &#160; Cl = 35 .5 )

Aicharya · Accepted Answer

C 2 O 4 - - + MNO 4 - → H + CO 2 m eq of C 2 O 4 - - = m eq of MNO 4 - 2 × 0 .225 90 = a × 5 ⇒ a = 0 . 001 mole = 1 milimole Mass of MnCl 2 = 1 × 55 + 71 = 126 mg

To measure the quantity of MnCl 2 dissolved in an aqueous solution, it was completely converted to KMnO 4…

Solution