A weak acid has a dissociation constant of K_a = 2.50 × 10^–2. 

a. Calculate the degree of dissociation for a 0.093m solution of this acid using the Debye–Hückel limiting law. 

b. Calculate the degree of dissociation for a 0.093m solution of this acid that is also 0.200m in KCl from the Debye–Hückel limiting law using an iterative calculation until the answer is constant in the second decimal place. 

c. Repeat the calculation in (b) using the mean activity coefficient for KCl in Table 10.3. Is the use of the Debye–Hückel limiting law advisable at the given KCl concentration? Do you need to repeat the iterative calculation of (a) to solve (b) and (c)?