This document provides information and examples related to titration calculations. It defines key terms like indicators, acids, alkalis and salts. It also outlines the step-by-step method for carrying out titration calculations, including determining moles of reagents from concentration and volume, identifying mole ratios from balanced equations, and calculating concentration from moles and volume. Several fully worked examples demonstrate how to apply this method to calculate unknown concentrations.

1. Titrations 1/28/2024
5 What is used to show
whether a solution is acidic,
alkaline or neutral?
4 Is potassium sulfate an acid,
an alkali or a salt?
3 Is calcium hydroxide an acid,
an alkali or a salt?
2 What type of reaction takes
place when an alkali reacts with
an acid?
1 What two substances are
formed when an acid reacts with
an alkali?
salt and water
neutralisation
alkali
salt
an indicator

2. Titrations 1/28/2024
6 What colour is
phenolphthalein in an alkaline
solution?
7 What colour is methyl orange
in an acidic solution?
8 What measuring instruments
are used to measure accurate
volumes of solutions in a
titration?
9 How many moles of solute
are there in 3 dm3 of 0.1 mol dm−3
hydrochloric acid?
10 How many moles of solute are
there in 110 cm3 of 0.1 mol dm−3
hydrochloric acid?
pink
red
burette and pipette
0.3 (mol)
0.011 (mol)

3. Titrations
28/01/2024
Calculate the concentration of:
1. 2 moles in 12 dm3
2. 3 moles in 9 dm3
3. 4 moles in 750 cm3
4. 12 moles in 4500 cm3
Concentration (mol dm-3) = Number of moles of solute/
Volume of solution in dm3

4. Titrations
28/01/2024
Calculate the concentration of:
1. 2 g of HCl in 12 dm3 water
2. 3 g of NaOH in 9 dm3 water
3. 4 g H2SO4 in 750 cm3 water
4. 12 g HNO3 in 4500 cm3 water
Moles = Mass/RMM
Followed by
Concentration (mol dm-3) = Number of moles of solute/ Volume
of solution in dm3

5. Titration calculations method
Step 1: Calculate the moles for whichever reagent you are given BOTH
the volume and the concentration.
Moles = (Concentration x Volume in cm3)/1000
Step 2: Check the mole ratio in the balanced equation.
e.g. NaOH + HCl  NaCl + H2O
Since there are no big numbers in front of the NaOH or HCl the mole ratio
is 1:1. If ratio is not 1:1, multiply or divide the moles from step 1 as
required.
Step 3: Use the number of moles calculated in Step 2 and the volume
given for the OTHER REAGENT in the question in the following equation:
Concentration = (1000 x moles)/Volume in cm3

6. Titrations 28/01/2024
Moles = concentration x volume (cm3) / 1000
How many moles in the following:
1. 25 cm3 of 1.235 mol/dm3 H2SO4 solution
2. 37 cm3 of 0.435 mol/dm3 KOH solution
3. 40 cm3 of 0.72 mol/dm3 HCl solution
4. 12 cm3 of 0.567 mol/dm3 NaOH solution
Step 1

7. Titrations 28/01/2024
What is the mole ratio between the acid and base in
the following equations:
1. HCl + NaOH = NaCl + H2O
2. H2SO4 + Ca(OH)2 = CaSO4 + 2H2O
3. 2HNO3 + Ca(OH)2 = Ca(NO3)2 + 2H2O
4. 3HNO3 + Al(OH)3 = Al(NO3)3 + 3H2O
Step 2
The mole ratio is the ratio of the chemical species in
a balanced equation.

8. Titrations 28/01/2024
Moles = concentration x volume (cm3) / 1000
If there are 0.25 moles of acid, how many moles of
base would there be in the following equations:
1. HCl + NaOH  NaCl + H2O
2. H2SO4 + Ca(OH)2  CaSO4 + 2H2O
3. 2HNO3 + Ca(OH)2  Ca(NO3)2 + 2H2O
4. 3HNO3 + Al(OH)3  Al(NO3)3 + 3H2O
Step 2
continued

9. Titrations 28/01/2024
Concentration = 1000 x moles/ volume
What is the concentration of:
1. 25 cm3 of solution that contains 0.75 moles
2. 38 cm3 of solution that contains 1.75 moles
3. 50 cm3 of solution that contains 0.75 moles
4. 27 cm3 of solution that contains 0.23 moles
Step 3

10. Titrations 28/01/2024
All steps!
25 cm3 of potassium hydroxide solution reacted
with 23.4 cm3 of 0.100 mol dm-3 hydrochloric acid.
KOH+HCL  KCl + H2O
Calculate the concentration of the KOH
Hint: BEFORE YOU START colour code or underline which pieces of information refer to
which reagent. A common mistake is to use the wrong values for the volume/conc of the
reagents.

11. Titrations 28/01/2024
Answer
Step 1: (0.1 x 23.4)/1000 =
0.00234 moles
Step 2: Ratio is 1:1 so moles of
KOH is also 0.00234
Step 3: (1000 x 0.00234)/25 =
0.936 mol dm-3

12. Another example
28/01/2024
25cm3 of sodium hydroxide solution was titrated against 0.15 mol
dm-3 hydrochloric acid. 21 cm3 of the acid neutralised the alkali.
HCl+ NaOH  NaCl + H2O
Calculate the concentration of the sodium hydroxide solution

13. Titrations 28/01/2024
Answer
Step 1: (0.15 x 21)/1000 =
0.00315 moles
Step 2: Ratio is 1:1 so moles of
NaOH is also 0.00315
Step 3: (1000 x 0.00315)/25 =
0.126 mol dm-3

14. Another example
28/01/2024
25 cm3 of potassium hydroxide solution
was neutralised by 35 cm3 of 0.75 mol
dm-3 sulfuric acid.
2KOH + H2SO4  K2SO4 + H2O
Calculate the concentration of the
potassium hydroxide

15. Titrations 28/01/2024
Answer
Step 1: (0.75 x 35)/1000 =
0.02625 moles
Step 2: Ratio is 2:1 (KOH:H2SO4)
so moles of KOH is
0.02625x2=0.0525
Step 3: (1000 x 0.0525)/25 = 2.1
mol dm-3