Ionic Strength and Activity Coefficient Calculation in Chemistry
How to calculate the ionic strength of a solution?
Given data: We have a solution that is 0.0003 M in Na3PO4 and 0.0002 molar in K3PO4. Calculate the ionic strength of the solution.
Calculation of Ionic Strength:
To calculate the ionic strength of the solution, we need to determine the contribution of each ion in the solution:
For Na3PO4:
- Na+ has a charge of +1 and a concentration of 0.0003 M.
- PO3- has a charge of -3 and a concentration of 0.0003 M.
Contribution of Na+: (0.0003 M) * (1) = 0.0003
Contribution of PO3-: (0.0003 M) * (-3) = 0.0009
For K3PO4:
- K+ has a charge of +1 and a concentration of 0.0002 M.
- PO3- has a charge of -3 and a concentration of 0.0002 M.
Contribution of K+: (0.0002 M) * (1) = 0.0002
Contribution of PO3-: (0.0002 M) * (-3) = 0.0006
Summing up the contributions:
Ionic strength = 0.0003 + 0.0009 + 0.0002 + 0.0006 = 0.0018