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 stoichiometric calculations in chemistry.

2. How Does the Calculator Work?

The calculator uses the molecular weight formula:

Where:

• \( MW \) — Molecular weight (g/mol)
• \( atomic\_masses \) — Standard atomic weights of elements (g/mol)
• \( counts \) — Number of atoms of each element in the molecule

Explanation: The calculator parses the chemical formula, identifies each element and its count, then sums the products of atomic masses and counts.

3. Importance of Molecular Weight

Details: Molecular weight is essential for preparing solutions, determining reaction yields, calculating molarity, 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). Element symbols are case-sensitive (Na for sodium, not NA).

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 expressed in grams per mole (g/mol) while molecular weight is dimensionless.

Q2: How are atomic weights determined?
A: Atomic weights are weighted averages of isotopic masses based on their natural abundance.

Q3: Can this calculator handle complex formulas?
A: It handles most standard chemical formulas but may not parse very complex notations like hydrates or coordination compounds.

Q4: What about elements with variable atomic weights?
A: The calculator uses standard atomic weights from IUPAC recommendations.

Q5: How accurate are the calculations?
A: Accuracy depends on the precision of the atomic weights used (typically 4-5 significant figures).