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)
• \( atomic\ masses \) — Array of atomic masses for each element in the molecule

Explanation: The calculator sums the atomic weights of all atoms in the molecule, multiplied by their respective counts.

3. Importance of Molecular Weight

Details: Molecular weight is essential for preparing solutions, calculating molarity, determining reaction yields, and in various analytical techniques like mass spectrometry.

4. Using the Calculator

Tips: Enter elements in the format "Symbol:Count" (e.g., "C:6,H:12,O:6" for glucose). Separate multiple elements with commas. Element symbols are case-sensitive (first letter uppercase, second lowercase if present).

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 reported with g/mol units).

Q2: How accurate are these calculations?
A: The calculator uses standard atomic weights. For precise work, use isotope-specific weights if needed.

Q3: Can I calculate formula weight for ionic compounds?
A: Yes, the same method works for ionic compounds (called formula weight rather than molecular weight).

Q4: What about hydrates or waters of crystallization?
A: Include water molecules in your calculation (e.g., "Cu:1,S:1,O:4,H:10" for CuSO₄·5H₂O).

Q5: How do I calculate molecular weight from a chemical formula?
A: Count each element in the formula (e.g., C₆H₁₂O₆ becomes C:6,H:12,O:6).