APPLIED SCIENCE
UNIT 13C INORGANIC
CHEMISTRY
DISTINCTION LEVEL
COMPLETE STUDY
GUIDE LATEST
UPDATE 2025/2026 BEST
FOR REVISION!!!
,Unit 13: Applications of Inorganic Chemistry
A: Investigate acid-base equilibria in order and to understand buffer action to
optimize acid-base titration procedures.
Acid or base?
Acid & Base Calculation Test
A weak acid is an acid that doesn't fully ionize when dissolved in water. An
example of a weak acid is ethanoic acid. Ethanoic acid reacts with water to produce
"hydroxonium ions and ethanoate ions". The ions easily react to reform the acid and
the water. The weak acid used was ethanoic acid.
Determining the acid dissociation constant (Ka) for a weak acid Aim:
The purpose of this experiment is to accurately demonstrate a reading of pH of a
half-neutralized solution of ethanoic acid and from this determine a value for Ka.
Introduction:
You will first accurately determine the titre of sodium hydroxide solution required to
neutralize 25.0 cm³ of 0.1M ethanoic acid. You will then
,neutralize exactly half of a new sample of 25.0 cm³ of ethanoic acid with sodium
hydroxide and accurately measure the pH of the resulting solution in order to
determine Ka.
Chemicals and Equipment:
• ethanoic acid (approx. 0.1M)
• sodium hydroxide solution (0.1M)
• safety spectacles
• 1 burette, 50 cm³, and stand
• 1 funnel, small
• pipette, 25.0 cm³, and pipette filler
• 1 beaker, 250 cm³
• 1 conical flask, 250 cm³
• distilled water
• pH meter (accurately calibrated)
CAUTION:
Sodium hydroxide solution is corrosive. You must wear safety spectacles throughout
the experiment.
Method:
1. Clamp the 50 cm³ burette to the stand. Using a funnel, rinse and fill the
burette with 0.1M sodium hydroxide solution.
2. Using a pipette filler, rinse the pipette with some of the ethanoic acid and
transfer precisely 25.0 cm³ of the solution into a 250 cm³ conical flask.
3. Add 2-3 drops of phenolphthalein indicator solution to the conical flask and
swirl to mix.
4. Run sodium hydroxide solution from the burette, swirling until the solution just
turns pink and is permanent.
5. Repeat the titration until you have obtained concordant titre. Calculate the mean
, titre (V cm³).
6. Pipette precisely 25.0 cm³ of the ethanoic acid solution this time into a 250
cm³ beaker. Do not add phenolphthalein indicator.
7. Run exactly V/2 cm³ of sodium hydroxide solution from the burette into the
beaker of ethanoic acid. This is the volume required to neutralize exactly half of the
ethanoic acid.
8. Swirl gently to ensure that the solutions are well mixed.
UNIT 13C INORGANIC
CHEMISTRY
DISTINCTION LEVEL
COMPLETE STUDY
GUIDE LATEST
UPDATE 2025/2026 BEST
FOR REVISION!!!
,Unit 13: Applications of Inorganic Chemistry
A: Investigate acid-base equilibria in order and to understand buffer action to
optimize acid-base titration procedures.
Acid or base?
Acid & Base Calculation Test
A weak acid is an acid that doesn't fully ionize when dissolved in water. An
example of a weak acid is ethanoic acid. Ethanoic acid reacts with water to produce
"hydroxonium ions and ethanoate ions". The ions easily react to reform the acid and
the water. The weak acid used was ethanoic acid.
Determining the acid dissociation constant (Ka) for a weak acid Aim:
The purpose of this experiment is to accurately demonstrate a reading of pH of a
half-neutralized solution of ethanoic acid and from this determine a value for Ka.
Introduction:
You will first accurately determine the titre of sodium hydroxide solution required to
neutralize 25.0 cm³ of 0.1M ethanoic acid. You will then
,neutralize exactly half of a new sample of 25.0 cm³ of ethanoic acid with sodium
hydroxide and accurately measure the pH of the resulting solution in order to
determine Ka.
Chemicals and Equipment:
• ethanoic acid (approx. 0.1M)
• sodium hydroxide solution (0.1M)
• safety spectacles
• 1 burette, 50 cm³, and stand
• 1 funnel, small
• pipette, 25.0 cm³, and pipette filler
• 1 beaker, 250 cm³
• 1 conical flask, 250 cm³
• distilled water
• pH meter (accurately calibrated)
CAUTION:
Sodium hydroxide solution is corrosive. You must wear safety spectacles throughout
the experiment.
Method:
1. Clamp the 50 cm³ burette to the stand. Using a funnel, rinse and fill the
burette with 0.1M sodium hydroxide solution.
2. Using a pipette filler, rinse the pipette with some of the ethanoic acid and
transfer precisely 25.0 cm³ of the solution into a 250 cm³ conical flask.
3. Add 2-3 drops of phenolphthalein indicator solution to the conical flask and
swirl to mix.
4. Run sodium hydroxide solution from the burette, swirling until the solution just
turns pink and is permanent.
5. Repeat the titration until you have obtained concordant titre. Calculate the mean
, titre (V cm³).
6. Pipette precisely 25.0 cm³ of the ethanoic acid solution this time into a 250
cm³ beaker. Do not add phenolphthalein indicator.
7. Run exactly V/2 cm³ of sodium hydroxide solution from the burette into the
beaker of ethanoic acid. This is the volume required to neutralize exactly half of the
ethanoic acid.
8. Swirl gently to ensure that the solutions are well mixed.
