The ion MnO₄^- is often used to analyze for the Fe²⁺ content of an aqueous solution by using the reaction MnO₄^- + Fe²⁺ $\rightarrow$ Fe³⁺ + Mn²⁺
In acidic solution. A 54.4-mL sample of a solution containing Fe²⁺ requires 33.3 mL of a 0.022 M KMnO₄ solution for complete reaction. What is the concentration of the Fe²⁺ in the original solution?

Question

The ion MnO₄^- is often used to analyze for the Fe²⁺ content of an aqueous solution by using the reaction MnO₄^- + Fe²⁺

\rightarrow

Fe³⁺ + Mn²⁺
In acidic solution. A 54.4-mL sample of a solution containing Fe²⁺ requires 33.3 mL of a 0.022 M KMnO₄ solution for complete reaction. What is the concentration of the Fe²⁺ in the original solution?

Quizplus · Accepted Answer

The balanced equation is:MnO₄^- + 5Fe²⁺ + 8H⁺ → 5Fe³⁺ + Mn²⁺ + 4H₂OFrom the stoichiometry of the balanced equation, we can see that 1 mole of MnO₄^- reacts with 5 moles of Fe²⁺. Therefore, the concentration of Fe²⁺ in the original solution can be calculated as follows:[Fe²⁺] = (0.022 M KMnO₄) x (33.3 mL KMnO₄) x (1 mol KMnO₄/1000 mL KMnO₄) x (5 mol Fe²⁺/1 mol KMnO₄) / (54.4 mL solution)= 6.7 x 10^-2 MTherefore, the correct answer is A.

The Ion MnO4- Is Often Used to Analyze for the Fe2+

The Ion MnO₄^- Is Often Used to Analyze for the Fe²⁺