Molar Mass & Chemical Formula Calculator
Compute chemical formula molar mass (g/mol) and element mass percentages.
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How to Use the Molar Mass Calculator: Molecular Weight & Elements
- 1Type your chemical formula into the input field (e.g., H2SO4 or C6H12O6).
- 2Review the calculated total molecular weight in grams per mole (g/mol).
- 3Inspect the elemental breakdown table showing atomic counts and weight percentages.
- 4Use the calculated molar mass for lab stoichiometry and solution preparation.
Formula & How It Works
IUPAC Atomic Weight Stoichiometry
Sums standard atomic weights multiplied by stoichiometric element frequency.
Worked Examples
Sulfuric Acid (H2SO4)
Input: H2SO4
Explanation: 2(1.008) + 32.065 + 4(15.999) = 2.016 + 32.065 + 63.996 = 98.077 g/mol.
Frequently Asked Questions
What is the difference between molar mass and molecular weight?▼
Molar mass has units of grams per mole (g/mol), whereas molecular weight is a dimensionless relative mass ratio.
What is Avogadro's number?▼
Avogadro's number is 6.02214076 × 10²³, representing the exact number of atoms or molecules in one mole of substance.
Why is case sensitivity critical when entering chemical formulas?▼
Element symbols must have a capitalized first letter (e.g., 'Co' is Cobalt, whereas 'CO' is Carbon Monoxide).
How are mass percentages calculated?▼
The total mass of each element in the formula is divided by the total molar mass of the compound and multiplied by 100.
Quick Reference & Conversion Table
| Compound | Common Name | Molar Mass (g/mol) | Primary Constituent |
|---|---|---|---|
| H2O | Water | 18.015 | Oxygen (88.8%) |
| NaCl | Table Salt | 58.443 | Chlorine (60.7%) |
| CO2 | Carbon Dioxide | 44.009 | Oxygen (72.7%) |
| C6H12O6 | Glucose | 180.156 | Oxygen (53.3%) |
⚠️ Common Pitfalls to Avoid
- •Typing element symbols in lowercase (e.g. 'co' for cobalt instead of 'Co', which confuses carbon and oxygen).
- •Omitting subscripts for polyatomic ions.
💡 Practical Real-World Uses
- •Calculating reagent masses required to synthesize chemical reactions in university labs.
- •Formulating pharmaceutical dosage compounds and industrial chemical blends.
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