Interactive Labs › Chemistry labs
CChemistryS4 to S6Industry
Industry lab: making soap
Soap is made in factories and small cooperatives from local oils. Calculate the exact recipe for safe, good soap and learn the chemistry behind it.
LevelS4 to S6 (and TVET)
TimeAbout 35 min
You useRatios, moles, pH, esters
PriceFree: no account
🎯 Aim
To calculate the amount of sodium hydroxide needed to make soap from different oils, and to explain saponification and the effect of excess alkali.
You will learn to
- Explain saponification of fats and oils.
- Calculate masses with saponification values.
- Calculate moles of sodium hydroxide.
- Explain superfat, pH and safety.
🧭 What to do
- Choose Palm oil and 1 kg. Read the NaOH needed.
- Move Sodium hydroxide per kg of oil and watch the pH and the result.
- Find the amount that gives about 5 % superfat.
- Try the other oils: which needs the most NaOH?
- Answer the questions with the class data.
- Write your conclusion and download your lab report.
📋 The data
Sodium hydroxide needed per kilogram of each oil (typical saponification values).
🧠 Investigate: answer from the data
Type your answer and tap Check. Use 💡 Hint first; open the method only when you are stuck.
➕ Get more from this experiment
📝 Free
Print the worksheet (button above), download the data, and save your report. Teachers can project this page in class.
📦 Premium Lab Pack
1 000 RWF
- Practical worksheet: a small cold-process soap with safety rules (teacher demonstration)
- Saponification calculations
- Teacher guide and answer key
- Exam-style questions with marking scheme
👩🏫 For teachers
Use it as a practical when apparatus is missing, as homework, or as a project. Free lesson plans help you plan, teach and assess.
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