Lab Practical

---
name: lab-practical
description: Science practical exam prep — experiments list, viva questions, lab record format. The practical component is part of the 20 IA marks.
---

# Lab Practical & Viva Prep

## Experiment List (CBSE 2026-27)

### Chemistry Experiments
```
1. pH determination: HCl, NaOH, ethanoic acid, lemon juice, water, NaHCO₃
   VIVA: What is universal indicator? Why is pH of NaOH >7?

2. Properties of acids/bases: reactions with litmus, zinc, Na₂CO₃
   VIVA: What gas evolves when acid reacts with metal? (H₂)

3. Reaction types observation:
   a) Combination: CaO + H₂O → Ca(OH)₂ (exothermic)
   b) Decomposition: FeSO₄ heating → Fe₂O₃ + SO₂ + SO₃
   c) Displacement: Fe nail in CuSO₄ → FeSO₄ + Cu
   d) Double displacement: Na₂SO₄ + BaCl₂ → BaSO₄↓ + NaCl
   VIVA: How do you identify a displacement reaction?

4. Reactivity series: Zn, Fe, Cu, Al with salt solutions
   VIVA: Why doesn't Cu displace Zn from ZnSO₄? (Cu is less reactive)

5. Acetic acid properties: odour, solubility, litmus, NaHCO₃ reaction
   VIVA: What is the IUPAC name of acetic acid? (ethanoic acid)

6. Soap in hard vs soft water
   VIVA: Why doesn't soap lather in hard water? (Ca²⁺/Mg²⁺ ions)
```

### Physics Experiments
```
7. Ohm's law: V-I graph, determine resistance
   VIVA: What is the slope of V-I graph? (resistance)
   VIVA: Why do we use rheostat? (to vary current)

8. Series and parallel resistance: find equivalent R
   VIVA: In which combination is total R less than individual R? (parallel)

9. Glass slab refraction: measure angles i, r, e
   VIVA: Why is emergent ray parallel to incident ray?

10. Glass prism: trace light path, observe dispersion
    VIVA: What is the order of colors in spectrum? (VIBGYOR)

11. Convex lens: image for different object distances, find f
    VIVA: At what position is image same size as object? (at 2F)
```

### Biology Experiments
```
12. Stomata: leaf peel mount, observe under microscope
    VIVA: What is the function of guard cells? (regulate stomatal opening)

13. CO₂ in respiration: KOH experiment with germinating seeds
    VIVA: Why do we use KOH? (absorbs CO₂, creates vacuum)

14. Binary fission (Amoeba) and budding (yeast): prepared slides
    VIVA: Is binary fission sexual or asexual? (asexual)

15. Dicot seed: identify embryo parts (radicle, plumule, cotyledon)
    VIVA: What develops into root? (radicle) Into shoot? (plumule)
```

## Lab Record Format
```
For each experiment:
  AIM: State clearly in one line
  MATERIALS: List all apparatus and chemicals
  PROCEDURE: Numbered steps
  OBSERVATION: Table format (what you saw)
  RESULT/CONCLUSION: One clear statement
  PRECAUTIONS: 2-3 bullet points
  
  ✅ Use ruled pages, neat handwriting
  ✅ Draw diagrams of setup with labels
  ✅ Complete on the SAME DAY as the experiment
```