1. What is Molar Mass?

Molar mass is the mass of one mole of a substance (chemical element or chemical compound) measured in grams per mole (g/mol) or unified atomic mass units (u). The exact molar mass is calculated using the exact masses of isotopes rather than average atomic weights.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( MW \) — Molar mass (u)
• Each atom's contribution is its exact isotopic mass multiplied by its count in the formula

Explanation: The calculator parses the chemical formula and sums the exact masses of all atoms present in the molecule.

3. Importance of Exact Molar Mass

Details: Exact molar mass is crucial for mass spectrometry, precise stoichiometric calculations, and isotopic studies. It differs from standard atomic weight which is an average of naturally occurring isotopes.

4. Using the Calculator

Tips: Enter the chemical formula using standard notation (e.g., H2O for water, C6H12O6 for glucose). The calculator recognizes element symbols and subscripts.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between molar mass and molecular weight?
A: Molar mass is the mass of one mole of substance (g/mol), while molecular weight is the mass of one molecule (u). Numerically they're equivalent but have different units.

Q2: Why use exact masses instead of average atomic weights?
A: Exact masses are needed for precise calculations, especially in mass spectrometry where isotopic distributions matter.

Q3: What elements are supported by this calculator?
A: The calculator supports common elements including H, C, N, O, Na, Cl, S, P, K, Fe, Ca, and Mg. More can be added as needed.

Q4: How accurate are the calculations?
A: The calculations use exact isotopic masses from IUPAC data, accurate to 6 decimal places.

Q5: Can this calculator handle complex formulas?
A: It handles standard chemical formulas with element symbols and subscripts. For more complex cases (parentheses, charges), a more advanced parser would be needed.