Class 12 science lab experiments are the prescribed practical activities in physics, chemistry and biology that a CBSE student performs, records and is examined on, separately from the theory paper. In the CBSE scheme for 2025–26, each science subject carries 70 marks for theory and 30 marks for a three-hour practical examination (CBSE, verified June 2026). These experiments build measurement, observation and reasoning skills and require specific apparatus, glassware and reagents. This step-by-step guide explains the core Class 12 physics, chemistry and biology experiments, the apparatus each needs, and how schools should specify and buy that apparatus, with links to the relevant categories on the Lab Exports products page.
| What are the Class 12 science lab experiments for CBSE? CBSE Class 12 science lab experiments fall into three subjects, each examined for 30 marks in a three-hour practical. Physics covers optics (focal length of mirrors and lenses), electricity (resistance, meter bridge, potentiometer) and electronics. Chemistry covers volumetric analysis (titration), qualitative salt analysis and a content-based experiment. Biology covers a major and minor experiment, slide preparation, spotting and an investigatory project. To perform them, a school needs compound microscopes, optics and electrical kits, borosilicate glassware, a 0.01 g balance and salt-analysis reagents. Review apparatus on the physics lab, chemistry lab and microscope categories, and confirm the current scheme at the CBSE academic portal. |
What are Class 12 science lab experiments?
Class 12 science lab experiments are the practical components of the CBSE physics (042), chemistry (043) and biology (044) courses, each assessed in a separate three-hour practical examination worth 30 marks against 70 marks for theory (CBSE practical syllabus, verified June 2026). A practical examination is defined as a supervised assessment in which a student performs experiments, prepares a record file, completes an investigatory project and answers a viva. The practical mark is added to the theory mark to give the subject total of 100 marks. Schools must equip a laboratory that lets every student perform the prescribed experiments safely and repeatably; confirm the current edition of the scheme at the CBSE academic portal before citing it in tender documents.
| Subject (CBSE code) | Theory Marks | Practical Marks | Practical Components |
| Physics (042) | 70 | 30 | Two experiments, one activity, record, project, viva |
| Chemistry (043) | 70 | 30 | Volumetric analysis, salt analysis, content experiment, project, viva |
| Biology (044) | 70 | 30 | Major + minor experiment, slide preparation, spotting, project, viva |
“In 30 years of supplying school labs, the practicals that lose marks are almost always the ones a school under-equipped — too few microscopes for the batch size, or glassware that is not graduated to the right class. Buy apparatus to the experiment list, not to the lowest quotation.” — Arvind Kumar, Lab Equipment Specialist, Lab Exports.
Core apparatus for Class 12 science lab experiments
The core apparatus for Class 12 science lab experiments is the minimum set of instruments, glassware and reagents needed to perform the prescribed physics, chemistry and biology practicals. The table below lists this apparatus with a procurement priority graded Essential (required to perform the core experiments), Required (needed for full syllabus coverage) and Recommended (improves throughput or accuracy). Product-name cells link to the relevant Lab Exports category.
| Apparatus | Subject / Use | Typical Specification | Priority |
| Compound microscope | Biology — slides, spotting | Monocular/binocular, 40×–1000×, LED | Essential |
| Borosilicate glassware set | Chemistry — titration, salt analysis | Borosilicate 3.3; burette 50 mL, pipette 20/25 mL | Essential |
| Optics kit | Physics — focal length, refraction | Concave/convex mirror & lens, f = 15–20 cm | Essential |
| Electrical kit | Physics — resistance, meter bridge | Galvanometer, resistance box, meter bridge | Essential |
| Laboratory balance | Chemistry — weighing reagents | 200 g × 0.01 g | Required |
| Salt-analysis reagent kit | Chemistry — qualitative analysis | Group reagents + acids/bases | Required |
| Permanent slide set | Biology — spotting, identification | Mitosis, meiosis, TS/LS slides | Required |
| pH meter | Chemistry — content experiment | 0–14 pH, ±0.01 pH | Recommended |
Schools that buy apparatus as subject-wise sets matched to the experiment list avoid shortfalls during the examination. Glassware is available on the lab glassware category, optics and electrical apparatus on the physics lab category, and microscopes on the microscope category.
How to conduct Class 12 physics practical experiments step by step
Class 12 physics practical experiments are grouped into optics, current electricity and electronics, and each is performed against a written procedure and recorded with observations and a graph. The CBSE physics practical (042) is examined for 30 marks and includes two experiments, one activity, a project and a viva (CBSE, verified June 2026). The worked example below shows the standard steps for a common optics experiment: finding the focal length of a concave mirror.
1. Mount the concave mirror on a stand and place it on the optical bench facing an illuminated object such as a wire gauze or candle.
2. Obtain a rough focal length by focusing a distant object onto a screen; record it as the approximate value.
3. Set the object at a distance greater than the rough focal length and move the screen until a sharp, real, inverted image forms.
4. Measure the object distance (u) and image distance (v) from the pole of the mirror and record both.
5. Repeat for at least five different object distances to obtain five sets of u and v.
6. Calculate the focal length for each set using f = uv / (u + v), and plot a u–v or 1/u–1/v graph.
7. Report the mean focal length with the unit in centimetres and state the sources of error.
Other prescribed Class 12 physics experiments include determining the resistance of a galvanometer by the half-deflection method, finding resistance with a metre bridge, and using a potentiometer. These need calibrated meters and resistance apparatus from the physics lab and lab meters categories.
Class 12 chemistry lab experiment procedure: titration and salt analysis
Class 12 chemistry practical experiments centre on volumetric analysis (titration), qualitative salt analysis and a content-based experiment, examined together for 30 marks (CBSE chemistry practical 043, verified June 2026). Volumetric analysis is defined as determining the concentration of a solution by reacting it with a standard solution of known concentration. The worked steps below cover a potassium permanganate (KMnO₄) titration against a standard reducing solution such as Mohr’s salt or oxalic acid.
1. Rinse the burette with KMnO₄ solution and fill it, removing air bubbles from the nozzle; KMnO₄ acts as its own indicator.
2. Pipette 20 mL of the standard reducing solution into a clean conical flask.
3. Add a measured volume of dilute sulphuric acid to provide the acidic medium; warm oxalic acid to about 60–70 °C if used.
4. Titrate by adding KMnO₄ dropwise with constant swirling until a permanent light-pink colour persists for about 30 seconds.
5. Record the initial and final burette readings and calculate the volume used.
6. Repeat until two or three concordant readings are obtained, then calculate the strength of the solution.
Qualitative salt analysis identifies one cation and one anion in a given salt through systematic group tests. The CBSE cation set includes Pb²⁺, Cu²⁺, Al³⁺, Fe³⁺, Mn²⁺, Ni²⁺, Zn²⁺, Co²⁺, Ca²⁺, Sr²⁺ and Ba²⁺ (CBSE chemistry practical, verified June 2026). Titration requires accurate borosilicate burettes from the burettes category, and salt analysis requires reagents from the lab chemicals category.
CBSE Class 12 biology practical step-by-step: slide preparation and spotting
CBSE Class 12 biology practical experiments are assessed for 30 marks across one major experiment (5), one minor experiment (4), slide preparation (5), spotting (7), practical record and viva (4) and an investigatory project (5) (CBSE biology practical 044, verified June 2026). Slide preparation is defined as making a temporary mount of biological material for observation under a microscope. The worked steps below show a temporary mount to observe mitosis in an onion root tip.
1. Grow onion root tips by suspending a bulb over water until roots are 2–3 cm long.
2. Cut the terminal 2–3 mm of a root tip early in the day when cell division is active.
3. Warm the tip gently in acetocarmine or aceto-orcein stain to colour the chromosomes.
4. Transfer the stained tip to a clean slide and add a drop of stain.
5. Place a coverslip and squash gently with thumb pressure to spread the cells into a single layer.
6. Observe under the compound microscope and identify the stages of mitosis.
Spotting requires students to identify permanent slides, specimens, charts and models within a fixed time. Adequate compound microscopes from the microscope category and permanent slide sets from the biology lab category are essential for both slide work and spotting.
Key specifications to check before buying Class 12 lab apparatus
Specifications for Class 12 lab apparatus should be written as a number with a unit and a reference, never as a vague descriptor. The specification table below lists the parameters a school should confirm in writing before purchase or tender. Each value should appear on the vendor’s quotation and on the delivered apparatus.
| Apparatus | Specification to Confirm | Why It Matters |
| Compound microscope | 40×–1000× magnification, LED illumination | Resolves cell and tissue detail for spotting |
| Burette | Borosilicate 3.3, 50 mL × 0.1 mL, Class A/B | Accurate volume delivery in titration |
| Pipette | 20 mL or 25 mL, Class A/B tolerance | Reproducible aliquots in volumetric analysis |
| Laboratory balance | 200 g × 0.01 g readability | Accurate reagent and sample weighing |
| Concave/convex mirror & lens | Focal length 15–20 cm, on stand | Standard optics experiments |
| Resistance box / metre bridge | Plug type, calibrated resistances | Resistance and meter-bridge experiments |
| pH meter | Range 0–14 pH, resolution ±0.01 pH | Content-based chemistry experiment |
| Permanent slides | Stained, labelled, mitosis/meiosis/TS/LS | Reliable spotting and identification |
Glassware tolerance class and microscope magnification are the two specifications most often under-stated in low-cost quotations. Confirm both against the lab glassware and microscope categories before approving a purchase.
Safety requirements for Class 12 science lab experiments
Safety requirements for Class 12 science lab experiments cover chemical handling, heat sources, electrical apparatus and biological material. A school laboratory must provide protective equipment, fume extraction for chemistry, and secure chemical storage. The bullet list and table below summarise the core precautions.
• Wear safety goggles and aprons during chemistry titration and salt analysis.
• Handle concentrated acids and KMnO₄ with care; add acid to water, never water to acid.
• Use fume extraction or a well-ventilated area for hydrogen sulphide and other gas tests.
• Keep flammable reagents away from spirit lamps and burners; store chemicals in a locked cabinet.
• Check that electrical apparatus is earthed and that meters are within rated voltage and current.
• Disinfect biology workspaces and dispose of biological material as per lab protocol.
• Keep a fire extinguisher, eyewash and first-aid kit accessible in the laboratory.
| Hazard | Precaution | Applies To |
| Corrosive chemicals | Goggles, aprons, acid-to-water rule | Chemistry titration, salt analysis |
| Toxic gases | Fume extraction / ventilation | Salt analysis (H₂S tests) |
| Open flame | Segregate flammables, heat shields | Chemistry, biology slide warming |
| Electrical | Earthing, rated meters | Physics electricity experiments |
| Biological material | Disinfection, safe disposal | Biology experiments |
Budget breakdown: equipping a Class 12 science lab for 30 students
The cost of equipping a Class 12 science laboratory depends on batch size, apparatus quality and the number of subjects. The figures below are estimated from Indian market benchmarks as of June 2026 and are inclusive of applicable GST; verify current pricing with vendors before procurement. The table models per-unit ranges for a 30-student batch.
| Item | Subject | Quantity (30 students) | Estimated Cost (INR) |
| Compound microscope (binocular) | Biology | 10–15 units | ₹4,000–₹15,000 each |
| Borosilicate glassware set | Chemistry | 10–15 sets | ₹8,000–₹25,000 per set |
| Laboratory balance (0.01 g) | Chemistry | 2–3 units | ₹6,000–₹25,000 each |
| Optics kit | Physics | 10–15 sets | ₹3,000–₹12,000 per set |
| Electrical kit | Physics | 10–15 sets | ₹5,000–₹20,000 per set |
| Salt-analysis reagent kit + chemicals | Chemistry | Bulk | ₹3,000–₹10,000 |
| Permanent slide set | Biology | 5–10 sets | ₹1,500–₹6,000 per set |
For multi-laboratory or government orders, unit costs typically fall while freight, installation and GST become significant line items quoted separately. Institutional and export buyers can request a consolidated written quotation through the Lab Exports OEM and tender page.
Pre-dispatch and acceptance checklist for lab apparatus
A pre-dispatch inspection protects a school from accepting apparatus that does not match the purchase specification. Run the following acceptance checklist before goods leave the vendor’s works, or on delivery for domestic orders. Sign off each step against the agreed specification.
1. Confirm microscope magnification, illumination and optical quality against the specification.
2. Verify glassware material (borosilicate 3.3) and graduation/tolerance class on each piece.
3. Test the laboratory balance against a standard weight to confirm 0.01 g readability.
4. Check optics kit focal lengths and the condition of mirrors and lenses.
5. Verify electrical apparatus ranges and that meters power on and read correctly.
6. Confirm reagent kit contents, purity grade and expiry dates.
7. Inspect permanent slides for staining, labelling and breakage.
8. Match all quantities against the purchase order for the stated batch size.
9. Confirm packaging is adequate for transit, especially on export consignments.
10. Obtain warranty documents, calibration certificates and operating instructions.
Vendor evaluation criteria for Class 12 lab apparatus suppliers
Selecting a lab apparatus supplier on price alone is the most common procurement error. The weighted criteria below give a structured way to score vendors. Keep specification compliance and safety above commercial terms.
| Evaluation Criterion | What to Verify | Suggested Weight |
| Specification compliance | Magnification, tolerance class, ranges match the spec | 25% |
| Quality and standards | Borosilicate grade, calibration, certifications | 20% |
| Syllabus coverage | Apparatus matches the full CBSE experiment list | 15% |
| Track record / experience | Years in business, school and institutional supply | 15% |
| After-sales and warranty | Warranty, spares, calibration support | 10% |
| Delivery and logistics | Lead time, packaging, export handling | 10% |
| Commercial terms | Price, payment terms, taxes and freight clarity | 5% |
A supplier that manufactures and exports educational laboratory apparatus, such as Lab Exports, can usually confirm syllabus coverage and quality more reliably than a pure trader. Request copies of stated certifications before award.
Common mistakes when equipping a Class 12 science lab
Mistake 1: Too few microscopes for the batch size
A 30-student biology batch sharing four microscopes cannot complete slide work and spotting in the examination time. Provide one microscope per one or two students and keep spares.
Mistake 2: Buying glassware without a tolerance class
Burettes and pipettes without a stated tolerance class give inconsistent titration results. Specify borosilicate 3.3 and Class A or B with the volume and graduation in millilitres.
Mistake 3: Ignoring balance readability
A balance that reads only to 0.1 g cannot support accurate volumetric analysis. Specify 200 g × 0.01 g readability and verify against a standard weight on delivery.
Mistake 4: Ordering reagents without checking expiry and purity
Salt-analysis reagents that are impure or expired produce wrong inferences. Confirm purity grade and expiry dates, and store reagents in a locked, ventilated cabinet.
Mistake 5: Specifying apparatus that does not cover the full syllabus
A kit that omits a metre bridge, potentiometer or specific slide set leaves part of the CBSE experiment list unteachable. Match the purchase to the current CBSE practical list verified at the CBSE academic portal.
Related guides and categories
• Physics lab equipment for optics and electricity experiments
• Chemistry lab equipment for titration and salt analysis
• Biology lab equipment for slide preparation and spotting
• Compound microscopes for biology practicals
• Laboratory glassware in borosilicate 3.3
• NCERT kits for activity-based practical work
• OEM and tender supply for bulk and institutional orders
Frequently asked questions
Which apparatus is needed for Class 12 physics, chemistry and biology practicals?
Class 12 practicals need compound microscopes and permanent slides for biology, borosilicate glassware and a 0.01 g balance for chemistry, and optics and electrical kits for physics, plus salt-analysis reagents. Buy apparatus as subject-wise sets matched to the CBSE experiment list and to the batch size. Review the apparatus on the physics lab and chemistry lab categories.
How many marks is the CBSE Class 12 practical exam?
The CBSE Class 12 practical examination carries 30 marks in each of physics, chemistry and biology, against 70 marks for theory, in the 2025–26 scheme (CBSE, verified June 2026). The practical is a three-hour examination covering experiments, a record file, an investigatory project and a viva. Confirm the current scheme at the CBSE academic portal before citing it in tender documents.
What safety precautions apply to Class 12 chemistry experiments?
Class 12 chemistry experiments require safety goggles and aprons, careful handling of concentrated acids and KMnO₄, ventilation or fume extraction for gas tests, and locked storage for reagents. Always add acid to water, never water to acid, and keep flammables away from open flames. A fire extinguisher, eyewash and first-aid kit must be accessible in the laboratory.
How much does it cost to set up a Class 12 science lab in India?
As of June 2026, compound microscopes are estimated at ₹4,000–₹15,000 each, borosilicate glassware sets at ₹8,000–₹25,000, and a 0.01 g balance at ₹6,000–₹25,000, inclusive of applicable GST; verify current pricing before procurement. Total cost depends on batch size and the number of subjects. For bulk orders, request a consolidated written quotation through the OEM and tender page.
How do I maintain a compound microscope and laboratory glassware?
Maintain a compound microscope by cleaning lenses only with lens tissue, storing it under a dust cover, and keeping it away from moisture; maintain glassware by rinsing immediately after use, avoiding thermal shock and checking for cracks before titration. Borosilicate 3.3 glassware tolerates heat but should still be handled carefully. Routine care preserves accuracy and extends apparatus life.
What is the difference between volumetric analysis and salt analysis in Class 12 chemistry?
Volumetric analysis determines the concentration of a solution by titrating it against a standard solution, while salt analysis identifies the cation and anion present in an unknown salt through systematic tests. Volumetric analysis is quantitative and uses burettes and pipettes; salt analysis is qualitative and uses group reagents. Both are examined within the 30-mark Class 12 chemistry practical.
Key takeaways
1. CBSE Class 12 physics, chemistry and biology each carry 70 marks for theory and 30 marks for a three-hour practical examination (CBSE, verified June 2026).
2. Class 12 physics practicals cover optics and electricity; chemistry covers titration and salt analysis; biology covers slide preparation, spotting and a project.
3. Buy apparatus as subject-wise sets matched to the CBSE experiment list and batch size, available across the physics lab and chemistry lab categories.
4. Specify glassware as borosilicate 3.3 with a stated tolerance class and balances at 200 g × 0.01 g, never as vague descriptors.
5. Score vendors on specification compliance and syllabus coverage before commercial terms, and run a pre-dispatch acceptance check.
6. For bulk, multi-lab or export orders, request a consolidated written quotation through the Lab Exports OEM and tender page.
• Lab Exports OEM and tender page
About Lab Exports
Lab Exports, headquartered at 11/315, Lalita Park, Laxmi Nagar, Delhi 110092, India, is an OEM manufacturer, supplier and exporter of scientific and educational laboratory equipment. Established in 1986, the company has more than three decades of supply experience and exports to over 60 countries, serving schools, colleges, universities, research institutions and hospitals. Lab Exports lists certifications including ISO 9001, ISO 13485 and ISO/IEC 17025 among others; buyers should request current certificates for tender use. Explore the full range below and contact the team for bulk supply, OEM and institutional procurement.