[chrisso80b]

How would I calculate the ionic strength for a 0.01M solution of Al₂(SO₄)₃
Im using the Ionic strength equation obviously but the fact that there are 2Al³⁺ ions for 3(SO₄)^2- ions confuses me...

Thanks!

[Borek]

Calculate separately concentrations of Al³⁺ and SO₄^2-.

[chrisso80b]

Because the concentration of the solution is 0.01M, and because I have Al₂ I said the concentration of Al= 0.01 x 2= 0.02M
I did the same with (SO₄) because I have 3 of them, I did 0.01 x 3= 0.03
So my calculation was:
1/2 (0.02 x 3³) + (0.03 x -2²)
And I got, 0.15. Is this right?

Thanks

[Borek]

0.15 is right even if 3³ is wrong.

[chrisso80b]

Oh yeh sorry i meant 3²

Thanks for the *delete me*