Question

If an aqueous 0.010 M solution of H₂SO₄ is prepared, the ionic strength is?

Answer 1

Recall that ionic strength considers all ions in solution, and its charges. It is typically used to calculate the ionic activity of other ions. The stronger the electrolytes, the more ionic strength they will have.

The formula:

I.S. = 1/2*sum( Ci * Zi^2)

Where

I.S. = ionic strength, M (also miu / μ ) used

Ci = concentration of ion “i”

Zi = Charge of ion “i”

The exercise

Assume 100% ionization so

[H+] =2*0.01 = 0.02 M

[SO4-2] = 0.01 M

then

IS = 1/2*(0.02*(1^2) + 0.01*(-2)^2)

IS = 0.03 M