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 various chemical calculations.

2. How Does the Calculator Work?

The calculator uses the molecular weight formula:

Where:

• \( MW \) — Molecular weight in g/mol
• \( \sum \) — Sum of all atomic masses in the molecule

Explanation: The calculator parses the chemical formula and sums the atomic weights of all constituent atoms.

3. Importance of Molecular Weight

Details: Molecular weight is essential for stoichiometric calculations, gas law applications, solution preparation, and determining physical properties of substances.

4. Using the Calculator

Tips: Enter the chemical formula using standard notation (e.g., H2O for water, CO2 for carbon dioxide). The calculator recognizes common elements and their atomic weights.

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 accurate are the atomic weights used?
A: The calculator uses standard atomic weights from PNNL data, which are based on IUPAC recommendations.

Q3: Can this calculator handle complex formulas?
A: It handles standard chemical formulas. For complex molecules or hydrates, use specialized software.

Q4: Why are some elements not recognized?
A: The calculator includes common elements. For less common elements, please check the periodic table.

Q5: Can I use this for ionic compounds?
A: Yes, but enter the empirical formula (e.g., NaCl for sodium chloride).