#17.1
Need to eliminate (Subscript[C, As]) from the rate equation...
Show that

\(C\_As\  = \ \(\(k\_g\) C\_Ag\  + \ k\*"""C\_Ae\)\/\(k\_g + k\*"""\)\)

And then the rxn rate expression will be similar to that of Example 17.3.

#17.3
Show first that

(Subscript[C, Ais]) = ((Subscript[k, 2])/((Subscript[k, 2]) + (Subscript[k, 3]))) (Subscript[C, Al])

Then eliminate (Subscript[C, Ais]) and (Subscript[C, Al]) and express the rate in terms of the OVERALL concentration gradient ((Subscript[C, Aig])-0). The final answer, as expected, should be a neat expression:

Rate = (1/((1/(Subscript[k, 1])) +  (1/(Subscript[k, 2])) + (1/(Subscript[k, 3]))))(Subscript[C, Ag])

#23.1
Your gas-film resistance, 1/((Subscript[k, Ag])a), should be 10, your liquid-film resistance,(Subscript[H, A])/((Subscript[k, Al]) aE), should be 10^3 (with E=1, because (Subscript[M, H])= 0.032 (Figure 23.4), and your chemical reaction resistance, (Subscript[H, A])/((Subscript[kC, B]) (Subscript[f, l])), should be 10^4.

#23.6
Your resistances here, respectively, should be 10, 5x10^-3 and 10^-8. Therefore, ?? is the RDS, and the reaction rate is 10 mol/h/m^3 reactor.

#25.3
τ = 1.5 h

#25.7
Reaction at the interface is the RDS

#25.8
Diffusion of A through the ash layer is definitely NOT the RDS. Reaction at the interface also does not appear to be the RDS, unless errors in the measurement of (Subscript[d, p]), t and (Subscript[X, B]) are relatively large.

LRR3@psu.edu