In: Chemistry
Calculate the ionic strength in a solution that contains 0.010 mol KCl, 0.005 mol MgCl2, 0.002 mol MgSO4, and 100g H2O.
density of water =1 g/cc
volume of water (v) = m/D = 100/1 = 100 ml
concentration of Kcl = n/V in L
= 0.01/0.1 = 0.001 M
concentration of MgCl2 = n/Vin L
= 0.005/0.1
= 0.0005 M
concentration of MgSO4 = n/Vin L
= 0.002/0.1
= 0.0002 M
Ionic strength(I) = 1/2*epsilon(Ci*Zi^2)
Ci = molarconcentration of ion i
Zi = charge number of ion i
I = 1/2([K+]*(+1)^2+[Cl-]*(-1)^2+[Mg^2+]*(+2)^2+[Cl-]*(-1)^2+[Mg^2+]*(+2)^2+[SO4^2-]*(-2)^2)
=
1/2*((0.001*(+1)^2)+(0.001*(-1)^2)+(0.0005*(+2)^2)+(0.0005*2*(-1)^2)+(0.0002*(+2)^2)+(0.0002*(-2)^2))
Ionicstrength(I) = 0.0033 M