1. Experiment Snapshot
Feature Details Experiment Preparation of a Standard Solution Exam Importance ⭐⭐⭐⭐ Practical exam standard Typical Marks 5–15 marks
2. Aim To prepare an accurate standard solution of known concentration using a volumetric flask.
3. Quick Theory A standard solution has an accurately known concentration. The solid must be weighed carefully, transferred completely, dissolved fully and made up exactly to the calibration mark.
Examiner Tip: Always connect the observation or reading to the purpose of the experiment.
4. Apparatus and Chemicals Apparatus Chemicals Balance, weighing boat, beaker, glass rod, funnel, volumetric flask, wash bottle, stopper. Primary standard solid and deionised water.
Safety: Wear goggles and follow teacher instructions, especially with acids, alkalis, hot apparatus and oxidising agents.
5. Step-by-Step Procedure Weigh the required mass of solid accurately. Transfer the solid into a beaker and dissolve it in deionised water. Use a funnel to transfer the solution into a volumetric flask. Rinse the beaker, glass rod and funnel into the flask. Make up to the calibration mark with deionised water. Stopper and invert several times to mix. 6. Observations / Results Situation Expected Result Correct final level Bottom of meniscus is on the calibration mark. If flask is overfilled Solution becomes too dilute.
7. Student Common Mistakes Forgetting to rinse the beaker and funnel into the flask. Filling above the calibration mark. Not mixing after making up to the mark. Losing solid during transfer. 8. Examiner Traps Trap: Students often describe the apparatus but forget the exact observation, reading, or endpoint. Use precise words.
8A. Labelled Diagram
In this experiment, the most important idea is controlled transfer. The solid must not be lost anywhere between the balance and the volumetric flask.
Preparation of a Standard Solution
Standard Solution Setup
balance
Weigh solid here
beaker
dissolve the solid first
volumetric flask
make up to the mark
wash bottle
rinse everything in
A clean transfer and careful rinsing are what make the solution accurate.
Teacher Voice: Tell students to think of this practical as “no solute left behind”. That is the habit the examiner is really testing.
9. 🎮 Interactive Simulator
Try It Yourself Which step prevents loss of solute during transfer?
-- Choose -- Rinse all apparatus into the flask Solution becomes too dilute Remove the funnel First permanent colour change Near the endpoint Blue-black colour disappears No Permanent pale pink Temperature change ΔT Exothermic What happens if water is added above the mark?
-- Choose -- Rinse all apparatus into the flask Solution becomes too dilute Remove the funnel First permanent colour change Near the endpoint Blue-black colour disappears No Permanent pale pink Temperature change ΔT Exothermic Run Simulator Reset Result Window Ready
Choose the correct actions to complete the practical.
Score: 0 /0
10. Past Paper Style Questions State the aim of this experiment. [2] Describe the procedure in order. [4] State one safety precaution. [2] State one common error and one improvement. [4] Explain the key observation/result. [3] 11. Mark Scheme Aim correct [2].
12. Mastery Checklist I can state the aim. I can name the apparatus and chemicals. I can describe the method in order. I know the result or endpoint. I can avoid student common mistakes. I can answer Section A questions.