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 as the sum of the atomic masses of all atoms in the molecule.

2. How to Calculate Molar Mass

The molar mass is calculated using the formula:

Where:

• \( MW \) — Molar mass (g/mol)
• \( \text{atomic masses} \) — Atomic weight of each element
• \( \text{counts} \) — Number of atoms of each element in the molecule

Example: For water (H₂O): (2 × 1.008 g/mol for H) + (1 × 15.999 g/mol for O) = 18.015 g/mol

3. Importance of Molar Mass

Details: Molar mass is essential for stoichiometric calculations, converting between mass and moles of a substance, preparing solutions, and determining empirical and molecular formulas.

4. Using the Calculator

Tips: Enter the chemical formula (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 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: 22.99 + 35.45 = 58.44 g/mol).

Q3: Where can I find atomic masses?
A: From the periodic table or IUPAC atomic weights. Our calculator has built-in atomic weights for common elements.

Q4: Does molar mass change with temperature?
A: No, molar mass is a constant property of each substance, unlike density which varies with conditions.

Q5: How precise are molar mass calculations?
A: Precision depends on the atomic weights used. Most calculations use 3-4 significant figures from standard atomic weights.