Lab Quick Reference
Essential Formulas, Conversions & Best Practices
Molarity (M)
moles = mass / MW
M = moles / Liters (L)
Moles of solute per liter of total solution.
Normality (N)
N = Molarity (M) × n
n = valence equivalents
Acids: H₂SO₄ (n=2), HCl (n=1).
Henderson-Hasselbalch
pH = pKa + log([A⁻]/[HA])
Calculate salt/acid ratio for target pH buffers.
Serial Dilution
Cn = C₀ × (1/Fold)^n
Where n is the number of dilution steps.
Unit Conversion Reference
| Type | Equivalent Units |
|---|---|
| Volume | 1 L = 1,000 mL = 1,000,000 µL |
| Mass | 1 g = 1,000 mg = 1,000,000 µg = 1,000,000,000 ng |
| Molar | 1 M = 1,000 mM = 1,000,000 µM |
| Temp | Kelvin (K) = Celsius (°C) + 273.15 |
💡 Analytical Pro Tips
- Always add Stock/Acid to Solvent, never water to concentrated acid.
- Use Volumetric Flasks for final volume adjustments (accurate to the meniscus).
- Allow solutions to reach Room Temp before final volume marking.
- R² Value: In calibration curves, >0.99 is the industry gold standard.