Question

This is the data from lab for the unknown concentration of a weak acid after mixture with 0.1 M NaOH

find the equivalence point, centration, and the pH of the weak acid

5.0	19.00
5.0	19.50
5.1	20.00
5.1	20.50
5.2	21.00
5.2	21.50
5.3	22.00
5.4	22.50
5.5	23.00
5.6	23.50
5.7	24.00
5.9	24.50
6.1	25.00
6.6	25.50
9.2	26.00
10.6	26.83
11.0	27.83
11.1	28.33
11.1	29.00

Answer 1

This is a strong base + weak acid titration

in the titration, we try to find the equivalence point

this point is given:

when pH changes the most in the table

for this:

6.6	25.50
9.2	26.00

meaning that the Volume of equivalnece is approx

26+25.5 = 25.75 mL approx

The data is not enough to get an exact pH equivalnece point

if this was the case

pH = pKa + log(A-/HA)

if half euqivlanec epoint --> 25.75 /2 = 12.88 mL

pH in V = 12.88 mL will be the pKA value

pH = pKa + log(1)