1. What is Molar Mass?

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

2. How to Calculate Molar Mass

The molar mass is calculated using the formula:

Where:

• \( MW \) — Molar mass (g/mol)
• \( Atomic\ Mass \) — Mass of each element (g/mol)
• \( Number\ of\ Atoms \) — Count of each element in the compound

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

3. Importance of Molar Mass

Details: Molar mass is essential for stoichiometric calculations, converting between mass and moles, and determining empirical and molecular formulas in chemistry.

4. Using the Calculator

Tips: Enter the chemical formula (e.g., H2O, CO2, NaCl). The calculator will sum the atomic masses of all elements in the compound.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between molecular weight and molar mass?
A: While often used interchangeably, molecular weight refers to the mass of one molecule, while molar mass refers to the mass of one mole of substance.

Q2: How do I calculate molar mass for hydrated compounds?
A: Include the water molecules in the calculation. For example, CuSO₄·5H₂O includes the masses of Cu, S, 4O, 10H, and 5O.

Q3: What are significant figures in molar mass calculations?
A: Typically report molar mass with 2-4 decimal places, depending on the precision of atomic mass values used.

Q4: How to handle parentheses in formulas?
A: Multiply the subscript outside parentheses by all elements inside. For Al₂(SO₄)₃: 2Al + 3S + 12O.

Q5: Where can I find accurate atomic mass values?
A: Use IUPAC standard atomic weights from the periodic table for most calculations.