Respuesta :
Answer: Molarity of [tex]KMnO_4[/tex] is 0.121 M
Explanation:
[tex]MnO_4^-(aq)+5Fe^{2+}(aq)+8H+(aq)\rightarrow Mn^{2+}(aq)+5Fe^{3+}(aq)+4H_2O(l)[/tex]
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.
[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]
where,
n= moles of solute
[tex]Moles=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{0.290g}{392g/mol}=7.40\times 10^{-4}mole[/tex]
[tex]V_s[/tex] = volume of solution = 10 ml
[tex]Molarity=\frac{7.40\times 10^{-4}\times 1000}{10}=0.074M[/tex]
According to the neutralization law:
[tex]n_1M_1V_1=n_2M_2V_2[/tex]
where,
[tex]M_1[/tex] = molarity of [tex]Fe^{2+}[/tex] solution = 0.074 M
[tex]V_1[/tex] = volume of [tex]FAS[/tex] solution = 10 ml
[tex]M_2[/tex] = molarity of [tex]KMnO_4[/tex] solution = ?
[tex]V_2[/tex] = volume of [tex]KMnO_4[/tex] solution = 12.23 ml
[tex]n_1[/tex] = valency of [tex]Fe^{2+}[/tex] = 2
[tex]n_2[/tex] = valency of [tex]KMnO_4[/tex] = 1
[tex]2\times 0.074\times 10=1\times M_2\times 12.23[/tex]
[tex]M_2=0.121[/tex]
Therefore, the molarity of [tex]KMnO_4[/tex] is 0.121 M
