146. Solving a chemistry problem

6. Calculate the ξ-potential on the quartz-aqueous solution of KCl, if the following data were obtained for electroosmosis: current strength J = 2⋅10 ^ -3 A; the transfer time of 4⋅10 ^ -8 m3 of the solution is 17 s; the specific electrical conductivity of the medium is κ = 6,2⋅10 ^ -2 Ω-1⋅m-1; ε0 = 8.85⋅10 ^ -12 F / m; ε = 81; the viscosity of the medium is η = 10 ^ -3 PaNs.