Question

0.05 mL of 0.04020m sodium salicylate was diluted with iron 3 chloride solution in a 100ml volumetric flask. what is the conc of the iron 3 salicylate in the flask?

Answer 1

3C₇H₅NaO₃ + FeCl₃ = (C₇H₅O₃)₃Fe + 3NaCl

$\rho$ (C₇H₅NaO₃) ≈ 1 g/ml

n (C₇H₅NaO₃) = C_m x m_(solvent) = 0.04020 x (0.05/1000)=0.00000201 mol

n ((C₇H₅O₃)₃Fe) = 1/3 x n (C₇H₅NaO₃) = 0.00000201/3 = 0.00000067 mol

$\rho$ ((C₇H₅O₃)₃Fe) ≈ 1 g/ml

C_m ((C₇H₅O₃)₃Fe) = 0.00000067 / ((100+0.05)/1000) = 0.000007 m