🎓 Chemistry • General Chemistry
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Molecular Weight Calculator
High-precision molecular weight evaluator for inorganic salts, organic molecules, and coordination complexes.
Chemical Formula Evaluator
Supports brackets, parenthesis, and hydrates (e.g. Ca(OH)₂, C₆H₁₂O₆, CuSO₄·5H₂O)
Total Molar Mass (Molecular Weight)
180.156 g/mol
Unified Mass (u / Da)
180.156 u
SI Molar Mass
0.180156 kg/mol
Total Atoms
24 atoms/molecule
Empirical Formula
CH2O
Visual Mass Fraction Breakdown
Total180.156g/mol
O (Oxygen)
53.3%
C (Carbon)
40.0%
H (Hydrogen)
6.7%
| Element | Atoms (n) | Standard Weight | Subtotal Mass | Mass Percent |
|---|---|---|---|---|
| O Oxygen Z = 8 • nonmetal | 6 | 15.999 | 95.994 g/mol | 53.28% |
| C Carbon Z = 6 • nonmetal | 6 | 12.011 | 72.066 g/mol | 40.00% |
| H Hydrogen Z = 1 • nonmetal | 12 | 1.008 | 12.096 g/mol | 6.71% |
Complete Chemical & Mathematical Derivation
1. Formula Decomposition: Found 3 unique elements totaling 24 atoms per formula unit. 2. Element-by-Element Mass Contributions: • Oxygen (O, Z=8): 6 atoms × 15.999 g/mol = 95.9940 g/mol (53.28%) • Carbon (C, Z=6): 6 atoms × 12.011 g/mol = 72.0660 g/mol (40.00%) • Hydrogen (H, Z=1): 12 atoms × 1.008 g/mol = 12.0960 g/mol (6.71%) 3. Total Molecular Mass: M = 95.994 + 72.066 + 12.096 = 180.1560 g/mol 4. Empirical Formula: CH2O (Common divisor = 6)
What is Molecular Weight?
Molecular weight is the ratio of the average mass of one molecule of an element or compound to one-twelfth of the mass of an atom of carbon-12.
Formula & Step-by-Step Calculation
MW = Σ (Count_i × AtomicWeight_i)
Total molecular mass in atomic mass units (u or Da).
Worked Step-by-Step Examples
Example 1
Molecular weight of Sulfuric Acid (H2SO4)
Solution: 98.079 g/mol
• 2(1.008) + 32.06 + 4(15.999) = 98.079 g/mol
Common Real-World & Academic Use Cases
- ✓ Pharmaceutical compound synthesis
- ✓ Polymer molecular weight estimation
- ✓ Gas density calculations
How to Use the Molecular Weight Calculator
1
Enter Molecular Formula
Input chemical notation.
2
View Molecular Weight
Inspect atomic breakdown in g/mol.
Frequently Asked Questions
Q: What is the difference between molecular weight and molar mass?
Molecular weight is dimensionless (or in Daltons), whereas molar mass is expressed in g/mol; numerically they are identical.