CBSE Class 12 Chemistry Practical and Viva 2026–27: Marks and Preparation
CBSE's 2026–27 Chemistry curriculum allocates 30 marks to practical evaluation. Good preparation connects the actual school record, observations, calculations, precautions and project work rather than memorising a detached list of viva answers.
Use this guide to organise practice, then verify the exact prescribed experiments and school schedule in the official curriculum and with the teacher conducting the course.
Official 30-mark evaluation scheme
The curriculum describes a three-hour practical examination and encourages micro-chemical methods wherever possible. Check the complete official list for the experiments and project guidance.
| Component | Marks |
|---|---|
| Volumetric Analysis | 8 |
| Salt Analysis | 8 |
| Content Based Experiment | 6 |
| Project Work | 4 |
| Class record and viva | 4 |
| Total | 30 |
Prepare volumetric analysis
- Know the purpose of each solution, apparatus choice and preparation step.
- Read the meniscus consistently and record observations immediately.
- Show the balanced reaction, calculation path, units and final result.
- Explain rinsing, endpoint choice and sources of error rather than reciting precautions.
- Repeat calculations from the student's own observation table without copying a model.
Prepare salt analysis
| Stage | Student should explain |
|---|---|
| Preliminary observation | What colour, odour, solubility or physical clue suggests and its limits. |
| Test | The reagent, condition and safe procedure. |
| Observation | The actual colour, precipitate, gas or change observed. |
| Inference | Why that observation supports or rules out an ion. |
| Confirmation | How the confirmatory test strengthens the conclusion. |
Review the content-based experiments
The official practical syllabus includes areas such as basic laboratory techniques, characterisation and purification, pH-related experiments, chemical kinetics, thermochemistry, electrochemistry, chromatography and preparation work. Use only the current prescribed list when making the record.
- For every performed experiment, know the aim, principle, apparatus, steps, observations, calculation or inference, result and precautions.
- Connect the experiment to the relevant theory chapter.
- Practise explaining why a step is done, not only what comes next.
- Use safe, teacher-supervised laboratory practice; a written guide does not replace lab instruction.
Use the record and project for viva preparation
Viva preparation should begin with the student's own record and project. Examiners can ask about choices, observations, calculations, limitations and conclusions from work the student claims to have completed.
- Explain one experiment from aim to result without reading.
- Defend one precaution by naming the error it prevents.
- Recalculate one result from recorded observations.
- Summarise the project question, method, evidence, limitations and conclusion.
- Correct incomplete labels, units and observations in the record before the examination.
A two-week preparation plan
| Days | Focus |
|---|---|
| 1–3 | Audit the record and rebuild the principle and calculation for volumetric analysis. |
| 4–6 | Practise the observation-to-inference chain for salt analysis. |
| 7–9 | Review performed content-based experiments and related theory. |
| 10–11 | Prepare the project explanation and likely evidence-led questions. |
| 12–13 | Run short viva rounds using the student's own record. |
| 14 | Complete a calm final review of apparatus, observations, units, safety and common errors. |
What parents can check
- The practical record is complete, legible and based on work performed at school.
- The student can explain observations and precautions in their own words.
- Calculations include formulae, substitution and units.
- Project claims match the recorded method and evidence.
- Any missing experiment access or teacher sign-off is raised with the school early.
Frequently asked questions
How many marks is the Class 12 Chemistry practical?
CBSE's 2026–27 curriculum allocates 30 marks: 8 each for volumetric and salt analysis, 6 for a content-based experiment, 4 for project work, and 4 for class record and viva.
Can I prepare the viva from common questions alone?
No. Start with the student's performed experiments, record and project, then explain principles, observations, calculations, precautions and limitations.
Can practical Chemistry be learned only online?
No. Laboratory work needs school supervision, apparatus practice and safety instruction. Online resources can help review the reasoning after proper practical experience.
PERSONAL SUPPORT
Strengthen the Chemistry behind the practical
Share the theory areas and experiments causing difficulty. TutorMax can discuss focused Class 12 Chemistry support around those gaps.
Discuss Chemistry support