Problem $1$:

Soil Type : $15\%$ kaolinite, $80\%$ montmorillonite, $5\%$ sand and others.

Pore water: $0\mathrm{.}0005MCaC{l}_2,$ Temperature $20C.$

Determine :

i$)$ The double layer thickness $($angstroms$)$

ii$)$ The surface potential.$($ mV $)$

iii$)$Potential at a distance $10$ angstroms. $($mV$)$