1. What is Molecular Weight?

Molecular weight (MW), also known as molecular mass, is the sum of the atomic weights of all atoms in a molecule. It's expressed in atomic mass units (u) or grams per mole (g/mol).

2. How to Calculate Molecular Weight

The molecular weight is calculated using the formula:

Steps to calculate:

1. Identify all atoms in the molecular formula
2. Find the atomic mass of each element from the periodic table
3. Multiply each atomic mass by the number of atoms of that element
4. Sum all the values to get the molecular weight

3. Importance of Molecular Weight

Details: Molecular weight is crucial in chemistry for stoichiometric calculations, preparing solutions with specific molar concentrations, and determining physical properties of substances.

4. Using the Calculator

Tips: Enter the chemical formula using standard notation (e.g., H2O for water, C6H12O6 for glucose). The calculator will sum the atomic masses of all atoms in the formula.

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 do I calculate MW for ionic compounds?
A: The process is the same - sum the atomic masses of all atoms in the formula unit (e.g., NaCl = Na + Cl).

Q3: What about hydrates?
A: Include the water molecules in the calculation (e.g., CuSO4·5H2O includes 5 water molecules).

Q4: How accurate is this calculator?
A: It uses standard atomic weights. For precise work, use isotope-specific masses.

Q5: Can I calculate MW for polymers?
A: For polymers, you typically calculate the molecular weight of the repeating unit multiplied by the degree of polymerization.