Answer:
C Fe³⁺ = 0.00109 M
Explanation:
The reaction between Fe(NO₃)₃ and KSCN is:
Fe³⁺(aq) + SCN⁻(aq) → FeSCN²⁺(aq)
5.9mL 4.4mL
0.0019M 0.0045M
The moles (η) of Fe(NO₃)₃ are:
[tex] \eta_{Fe(NO_3)_3} = C_{Fe(NO_3)_3} \cdot V_{Fe(NO_3)_3} = 0.0019 mol/L \cdot 5.9 \dot 10^{-3} L = 1.121 \cdot 10 ^{-5} moles [/tex]
Since in 1 mol of Fe(NO₃)₃ we have 1 mol of Fe³⁺, the moles of Fe³⁺ are:
[tex] \eta_{Fe^{3+}} = \eta_{Fe(NO_3)_3} = 1.121 \cdot 10 ^{-5} moles [/tex]
Now, to calculate the initial concentration of Fe³⁺ we need first to find the total volume in the final solution:
[tex] V_{T} = V_{Fe(NO_3)_3} + V_{KSCN} = 5.9 mL + 4.4 mL = 10.3 mL = 0.0103 L [/tex]
Finally, the the initial concentration of Fe³⁺ is:
[tex] C_{Fe^{3+}} = \frac{\eta_{Fe^{3+}}}{V_{T}} = \frac{1.121 \cdot 10 ^{-5} moles}{0.0103 L} = 0.00109 M [/tex]
I hope it helps you!
