Question

This question provides an example calculation to help you determine the molarity of the FeSCN ²⁺ solutions at equilibrium from experimental data.

For the following results:

Absorbance, Trial 2: 0.214 ;

Absorbance of standard solution : 0.549

Concentration of standard solution : 0.000200 M

The concentration of FeSCN ²⁺ at equilibrium for this trial is [a] M

Answer 1

As we know A = se el A = Absorbances of solution E = moles extinsic coefficient C = come of solution l = length of the tube so A alpha C so, A_1/A_2 = C_1/C_2 A_1 = absorbances of trail 2 = 0.214 C_1 = cano of the Fesen^2+ = ?(unknown)[a] A_2 = Absorbances of standard solution = 0.549 C_2 = cone of standard FeSen^2+ solution = 0.000200M Now 0.214/0.549 = C_1[a]/0.0002 as, [a] = 7.796 times 10^-5 M Hence the come of FeSen ^2+ of equal this trail = 7796 times 10^-5(M)