1. What is Molecular Weight?

Molecular weight (MW) is the sum of the atomic weights of all atoms in a molecule. It's expressed in atomic mass units (amu) or grams per mole (g/mol) and is crucial for chemical calculations and stoichiometry.

2. How Does the Calculator Work?

The calculator uses the molecular weight formula:

Where:

• \( MW \) — Molecular weight (g/mol)
• \( atomic\ masses \) — Array of atomic masses for each element in the molecule

Explanation: The calculator parses the chemical formula, looks up each element's atomic weight, multiplies by the number of atoms, and sums all values.

3. Importance of Molecular Weight

Details: Molecular weight is essential for preparing solutions, calculating molarity, determining reaction yields, and understanding physical properties of substances.

4. Using the Calculator

Tips: Enter the chemical formula using standard notation (e.g., H2O for water, C6H12O6 for glucose). Capitalization matters (Co is cobalt, CO is carbon monoxide).

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between molecular weight and molar mass?
A: They are numerically identical but molar mass is the mass of one mole of substance (g/mol), while molecular weight is dimensionless (though often expressed in g/mol for convenience).

Q2: How do I enter formulas with parentheses?
A: This calculator handles simple formulas without parentheses. For complex formulas like Ca(OH)2, use separate calculations for each part.

Q3: Are isotopes considered in the calculation?
A: No, the calculator uses average atomic weights from the periodic table which account for natural isotope abundance.

Q4: Why is my calculated MW slightly different from published values?
A: Different sources may use slightly different atomic weight values due to updates in measurement techniques.

Q5: Can I calculate formula weight for ionic compounds?
A: Yes, the same calculation applies to ionic compounds, though we technically call it "formula weight" rather than "molecular weight."