Molar Mass Calculator

Molar Mass Formula:

\[ \text{Molar Mass} = \sum (\text{Atomic Mass} \times \text{Number of Atoms}) \]

Molar Mass:

1. What is Molar Mass?

Molar mass is the mass of one mole of a substance (chemical element or chemical compound). It is expressed in grams per mole (g/mol) and is calculated by summing the atomic masses of all atoms in a molecule.

2. How to Calculate Molar Mass

The formula for calculating molar mass is:

\[ \text{Molar Mass} = \sum (\text{Atomic Mass} \times \text{Number of Atoms}) \]

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

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 molar mass = 2.016 + 15.999 = 18.015 g/mol

3. Importance of Molar Mass

Details: Molar mass is fundamental in chemistry for:

Converting between grams and moles of a substance
Preparing solutions with specific concentrations
Stoichiometric calculations in chemical reactions
Determining empirical and molecular formulas

4. Using the Calculator

Tips:

Enter the chemical formula using standard notation (e.g., H2O, C6H12O6)
Element symbols are case-sensitive (first letter uppercase, second lowercase)
Subscripts indicate the number of atoms (omit if 1)

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between molar mass and molecular weight?
A: They are numerically the same but molar mass has units of g/mol while molecular weight is dimensionless.

Q2: How do I calculate molar mass for ionic compounds?
A: The same way - sum the atomic masses of all atoms in the formula unit (e.g., NaCl = Na + Cl).

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

Q4: Why are my calculated values slightly different from published values?
A: Different sources may use slightly different atomic weight values (especially for elements with multiple isotopes).

Q5: How accurate is this calculator?
A: It uses standard atomic weights but for precise work, always use the most current IUPAC values.