CHEMISTRY 12 WORKSHEET 4.10
Titrations and Titration Curves
1. Calculate the pH of the solution resulting from the following reactions:
a) 30.0 ml of 0.20 M NaOH and 30.0 ml of 0.20 M HCl
b) 30.0 ml of 0.20 M NaOH and 40.0 ml of 0.20 M HCl
c) 50.0 ml of 0.10 M CH3COOH and 50.0 ml of 0.10 M KOH
d) 10.0 ml of 0.10 M HClO4 and 10.0 ml of 0.10 M NH3
2. For each of the following titrations, specify which indicator from column 2 that
should be used. Give a reason for your answer.
Column 1 (reaction)
Column 2 (indicator)
a) NaOH + KHC8H4O4
neutral red (6.8-8.0)
b) CsOH + HClO4
bromocresol green (3.8-5.4)
c) KHCO3 + HCl
ortho-cresolphthalein (8.2-9.8)
3. The following data is obtained during the titration of 25.0 ml of propanoic acid
with 0.100 M NaOH.
Initial pH = 2.950
Volume of NaOH used 23.8 ml
pH at 11.9 ml = 4.873
a) What is the Ka for propanoic acid?
b) What is the [propanoic acid] based on the [NaOH] and the volumes of the
reactants?
c) What is the [propanoic acid] as calculated from your Ka and the initial pH
value?
4. The following data is obtained during the titration of aniline (C6H5NH2) with
0.100 M HCl.
Initial pH = 8.72
Volume of HCl used = 16.32 ml
pH at 8.16 ml = 4.63
a) What is the Ka for aniline?
b) What is the original [aniline]
5. The titration of a solution of benzoic acid required 28.4 ml of 0.125 M NaOH.
The initial pH of the acid is 2.628 and the pH is 4.191 after 14.2 ml of the NaOH
added.
a) What is the Ka for the benzoic acid?
b) What is the original [benzoic acid]