Titrations Calculations

A titration experiment is a scientific procedure designed to determine how concentrated an acid

or base is by using the opposite solution.

What is Titration ?

By figuring out how much of the known solution to use, you can find the

concentration of the unknown solution.

Titrations Calculations

Titration Calculations - Procedure

ACID ALKALI

Split the page into two sections.Labelled acid and alkali.

Look at the clues to determine the following factors for each side.

N = Number of MolesC = Conc in Mol/l

V = Volume in Litres.

1. Gather all the suspects in the one place.

Step 1 – Write out the balanced equation for the neutralisation reaction.

2. Establish relationships between the suspects.

Step 2 – Determine the “mole ratio” between the alkali and the acid.

3. Split the prime suspects and collect all the known” evidence on each !

Step 3

Titration Calculations - Procedure

4. Having gathered all the evidence it should now be obvious how to solve the case however some final interrogation could be required. !

5. With the final interrogation complete you are now ready to solve the case.

Step 4 – Use the “mole ratio” to establish the N value for the unknown solution

Step 5 – Use the triangle to complete the calculation

N

C V

Titration Calculations - ExampleIf 25cm3 of a solution of sodium hydroxide is exactly neutralised by 13.5 cm3 of 0.6 mol/l sulphuric acid, what is the concentration of the

alkali?

ALWAYS WRITE THE BALANCED EQUATION FIRST !

NaOH +

H2S04 Na2SO4 +

H202 2

Once you gather all the suspects - Now the “Detective” work starts !!!

ACID ALKALI

Split the page into two sections.Labelled acid and alkali.

Look at the clues to determine the following factors for each side.

N = Number of MolesC = Conc in Mol/l

V = Volume in Litres.

Titration Calculations - ExampleIf 25cm3 of a solution of sodium hydroxide is exactly neutralised by 13.5 cm3 of 0.6 mol/l sulphuric acid, what is the concentration of the

alkali?

ALWAYS WRITE THE BALANCED EQUATION FIRST !

NaOH +

H2S04 Na2SO4 +

H202 2

Once you gather all the suspects - Now the “Detective” work starts !!!

ACID ALKALI

V = 0.0135 Litres V = 0.025 Litres

C = 0.6 mol / l C = ?

N = ? = C x V = 0.6 x 0.135 = 0.0081

N alkali = 2 x N acid

= 2 x 0.0081 = 0.0162

Titration Calculations

N

C V

Concentration For Sodium Hydroxide = N / V

0.0162 = 0.025

= 0.648 Moles / Litre

Now It’s Your Turn to Solve a Few Mysteries

N

C V

Well Done.The Case is Solved.