Exam Tips
Top 15 Most Important Chemistry Formulas for Class 11 & 12 Students (Hinglish) | Board, NEET & JEE Revision Notes
30 Jun 2026
Top 15 Important Chemistry Formulas (Class 11 & 12)
Revision notes for Board, NEET & JEE.
| No. | Formula | Use |
|---|---|---|
| 1 | n = W / M | Number of moles |
| 2 | W = n × M | Mass |
| 3 | N = n × 6.022 × 10²³ | Particles |
| 4 | n = N / 6.022 × 10²³ | Moles from particles |
| 5 | Molar Mass = Molecular Mass (g/mol) | Molar mass |
| 6 | Density = Mass / Volume | Density |
| 7 | Volume = Mass / Density | Volume |
| 8 | Average Atomic Mass = Σ(Isotope Mass × Abundance)/100 | Average atomic mass |
| 9 | Neutrons = Mass No. − Atomic No. | Neutrons |
| 10 | Protons = Atomic No. | Protons |
| 11 | PV = nRT | Ideal Gas Law |
| 12 | P₁V₁ = P₂V₂ | Boyle's Law |
| 13 | V₁/T₁ = V₂/T₂ | Charles' Law |
| 14 | P₁/T₁ = P₂/T₂ | Gay-Lussac's Law |
| 15 | V₁/n₁ = V₂/n₂ | Avogadro's Law |
Exam Tips
- Daily formula revision.
- Units always check karo.
- Mole Concept & Gas Laws are very important.