1. What is Molar Mass?

Molar mass is the mass of one mole of a substance (chemical element or chemical compound). It is a physical property defined as the mass of a given substance divided by the amount of substance. The molar mass of water (H₂O) is approximately 18.015 g/mol.

2. How to Calculate Molar Mass of H₂O

The molar mass of water is calculated by summing the atomic masses of its constituent atoms:

Where:

• H — Hydrogen (standard atomic mass ≈ 1.008 g/mol)
• O — Oxygen (standard atomic mass ≈ 15.999 g/mol)

Example Calculation: Using standard atomic weights: (2 × 1.008) + 15.999 = 18.015 g/mol

3. Importance of Molar Mass

Details: Molar mass is crucial for converting between grams and moles of a substance, which is fundamental in stoichiometric calculations, solution preparation, and chemical analysis.

4. Using the Calculator

Tips: Enter the atomic masses of hydrogen and oxygen. Default values are provided based on standard atomic weights. The calculator will compute the molar mass of water (H₂O).

5. Frequently Asked Questions (FAQ)

Q1: Why is the molar mass of water approximately 18.015 g/mol?
A: This value comes from the weighted average of all naturally occurring isotopes of hydrogen and oxygen.

Q2: How does molar mass differ from molecular mass?
A: Molecular mass is the mass of a single molecule (in atomic mass units, u), while molar mass is the mass of one mole of molecules (in g/mol).

Q3: Why do we multiply hydrogen by 2 in the calculation?
A: Because each water molecule contains two hydrogen atoms (H₂O).

Q4: Can I use this calculator for other molecules?
A: This specific calculator is designed for H₂O only. The same principle can be applied to other molecules by adjusting the formula.

Q5: How accurate are the standard atomic weights?
A: Standard atomic weights are based on measurements of isotopic abundance in natural terrestrial sources and are regularly updated by IUPAC.