1. What is Molecular Weight?

Molecular weight (MW), also called molecular mass or molar mass, 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).

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• Each element's standard atomic weight is used
• Subscripts in the formula indicate the number of atoms
• The sum is calculated for all atoms in the molecule

Example: For H₂O (water), MW = (2 × 1.008) + 15.999 = 18.015 g/mol

3. Importance of Molecular Weight

Details: Molecular weight is crucial for stoichiometric calculations, preparing molar solutions, determining empirical formulas, and understanding physical properties like boiling point.

4. Using the Calculator

Tips: Enter the chemical formula using standard notation (e.g., 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 formula weight?
A: Molecular weight refers to molecules, while formula weight is used for ionic compounds that don't form discrete molecules.

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

Q3: Can I calculate MW for complex formulas?
A: Yes, the calculator handles formulas with multiple elements and subscripts (e.g., Ca3(PO4)2).

Q4: What if my formula contains parentheses?
A: The calculator currently doesn't support parentheses. For formulas like (NH4)2SO4, input as N2H8SO4.

Q5: Why are atomic weights not whole numbers?
A: Atomic weights account for natural isotopic abundance of each element.