1. What is Molecular Mass?

Molecular mass (or molecular weight) is the sum of the atomic masses of all the atoms in a molecule. It's expressed in atomic mass units (u) 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 mass formula:

Where:

• Atomic Mass — The mass of a single atom of the element (from periodic table)
• Number of Atoms — How many atoms of that element are in the molecule
• Σ — Sum of all elements in the compound

Example: For water (H₂O):

• 2 Hydrogen atoms: 2 × 1.008 g/mol = 2.016 g/mol
• 1 Oxygen atom: 1 × 15.999 g/mol = 15.999 g/mol
• Total molecular mass = 2.016 + 15.999 = 18.015 g/mol

3. Importance of Molecular Mass Calculation

Details: Molecular mass is essential for:

• Balancing chemical equations
• Calculating molar concentrations
• Determining reaction yields
• Preparing solutions with specific molarities
• Converting between mass and moles of a substance

4. Using the Calculator

Tips:

• Enter elements as symbol followed by number of atoms (e.g., "H2,O1" for water)
• Element symbols are case-sensitive (first letter uppercase, second lowercase)
• If no number is given after element symbol, 1 atom is assumed
• Separate different elements with commas

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between molecular mass and molar mass?
A: They are numerically identical but molar mass refers to one mole of substance while molecular mass refers to a single molecule.

Q2: How do I calculate molecular mass for ionic compounds?
A: The same way - sum the atomic masses of all atoms in the formula unit (called formula mass for ionic compounds).

Q3: Why are atomic masses not whole numbers?
A: Atomic masses account for natural isotopic abundances - they're weighted averages of all naturally occurring isotopes.

Q4: How accurate are these calculations?
A: They're as accurate as the atomic mass values used. For most purposes, 2-4 decimal places are sufficient.

Q5: What if my compound contains parentheses or dots?
A: This calculator handles simple formulas. For hydrates (e.g., CuSO₄·5H₂O) or complex formulas, enter as "Cu1,S1,O4,H2,O1" etc.