Strong base to weak acid titration curve: combining all equations

In summary, the pH curve of a strong base to weak acid titration can be described by the following simplified equations in place of a complex complete pH titration equation:

Start point	$pH=\frac{pK_a-log[HA]_{ud}}{2}\; \; \; \; \; \; \; \; (1)$
After start point but before stoichiometric point	$pH=pK_a+log\frac{[A^-]_s}{[HA]_r}\; \; \; \; \; \; \; \; (2)$
Maximum buffer capacity point	$pH=pK_a\; \; \; \; \; \; \; \; (3)$
Stoichiometric point	$pH=\frac{pK_w+pK_a+log[A^-]}{2}\; \; \; \; \; \; \; \; (4)$
Beyond stoichiometric point	$pH=pK_w+log[OH^-]_{ex}\; \; \; \; \; \; \; \; (5)$

The diagram below shows the plot of the above equations on a single graph for the titration of 10 cm³ of 0.200 M of CH₃COOH (K_a = 1.75 x 10^-5) with 0.100 M of NaOH:

A complementary set of equations can be derived using the same logic mentioned in the earlier articles to describe a strong acid to weak base titration.

Strong base to weak acid titration curve: combining all equations

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