Please answer A and B, they are both part of the same question

Benzene is a major component of gasoline. Toluene is another compound present in gasoline in smaller concentrations (about 7% by weight). Gasoline was leaked from a storage tank into the surrounding soil. The logKOC for benzene is 1.79 and for toluene is 2.15 (L kg-1 C). In the region contaminated with gasoline, the organic C content of the soil is 3% near the soil surface.

a)Assuming that n=1 (Freundlich exponent), determine the partition coefficients (KD) and plot sorption isotherms for both benzene and toluene. (The relevant Cw ranges from 0 to 40 mmol L-1.)

b)What do you conclude about the relative mobility of benzene and toluene in soil?

Example to answer the question:

Kd=foc*Koc; logKoc= 1.23 ; Koc= 17L/kgC ; surface soil %=1.5 oc => Kd=(.015kgLC/kgsoil)(17L/kgC)= .255 L/kgsoil

For the graph Cs=Kd*Cw (x-axis from 0 to 40 mmol/L & Cw, y-axis Cs)