Question

Effect of pK_a in the titration of weak acid with strong base.Use Equation 11-13 to compute and plot the family of curves at the left side of Figure 11-3. For a strong acid, choose a large K_a, such as K_a = 10² or pK_a = -2

Short answer

The plot of the family of curves is shown below

Step-by-step solution

Equation need to be used to develop spreadsheet

The equation for the fraction of titration of weak acid with strong base

$\varphi =\frac{C_b{V}_b}{C_a{V}_a}=\frac{{\alpha }_{A^{-}}-1-{\displaystyle \frac{\left[H^{+}\right]-\left[O{H}^{-}\right]}{C_a}}}{1+\frac{\left[H^{+}\right]-\left[O{H}^{-}\right]}{C_b}}$

Consider the titration of a weak acid HA (volume=V_a, initial concentration=C_a) with a strong base NaOH (volume=V_b, initial concentration=C_b).

The respective values were taken as per the information given equation 11-13 and figure 11-3.

Spreadsheets developed for different pKa values

Spreadsheet for different pK_a values

Final plot

From the above data family of curves were plotted