Ionic strength of 0.1M of Fe2(SO4)2 IS?

Question

Answer

Calculation of Ionic Strength of 0.1M Fe2(SO4)2 Solution

Step 1: Write the balanced chemical equation for the dissociation of Fe2(SO4)2

Fe2(SO4)2 → 2 Fe2+ + 2 SO42-

Step 2: Calculate the concentration of each ion

[Fe2+] = 2 x 0.1M = 0.2M

[SO42-] = 2 x 0.1M = 0.2M

Step 3: Calculate the activity coefficient for each ion using Debye-Hückel equation

γ± = 10^(-0.509*(z±)^2*(I^0.5)/(1+1.224*(I^0.5)))

Where z± is the charge of the ion and I is the ionic strength of the solution.

For Fe2+ ion:

z+ = 2

I = 1/2 x (2 x 0.2M x (2^2)) = 0.4M

γ+ = 10^(-0.509*(2)^2*(0.4^0.5)/(1+1.224*(0.4^0.5))) = 0.538

For SO42- ion:

z- = -2

I = 1/2 x (2 x 0.2M x (-2)^2) = 0.4M

γ- = 10^(-0.509*(-2)^2*(0.4^0.5)/(1+1.224*(0.4^0.5))) = 0.538

Step 4: Calculate the ionic strength of the solution

I = 1/2 x (Σci zi^2)

I = 1/2 x [(0.2M x 2^2) + (0.2M x (-2)^2)] = 0.4M

Step 5: Calculate the sum of the activity coefficients weighted by the concentration of each ion

Σci γi ± = (0.2M x 0.538) + (0.2M x 0.538) = 0.215

Step 6: Calculate the ionic strength of the solution

μ = (1/2) x Σci zi^2 γi ±

μ = (1/2) x [(0.2M x 2^2 x 0.538) + (0.2M x (-2)^2 x 0.538)] = 0.430

Step 7: Calculate the ionic strength of the solution

I = (1/2)