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).

2. How is Molecular Mass Calculated?

The molecular mass is calculated by:

Where:

• Atomic Mass of Hydrogen (H) = 1.008 g/mol
• Atomic Mass of Sulfur (S) = 32.06 g/mol
• Atomic Mass of Oxygen (O) = 16.00 g/mol

Example: For H₂SO₄:

• 2 Hydrogen atoms × 1.008 g/mol = 2.016 g/mol
• 1 Sulfur atom × 32.06 g/mol = 32.06 g/mol
• 4 Oxygen atoms × 16.00 g/mol = 64.00 g/mol
• Total = 2.016 + 32.06 + 64.00 = 98.076 g/mol

3. Importance of Molecular Mass

Details: Molecular mass is essential for stoichiometric calculations, preparing solutions with specific molar concentrations, and understanding chemical reactions.

4. Using the Calculator

Tips: Enter the number of each type of atom in your molecule. The calculator uses standard atomic weights to compute the total molecular mass.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between molecular mass and molar mass?
A: They are numerically identical but molecular mass refers to a single molecule while molar mass refers to one mole (6.022×10²³ molecules) of the substance.

Q2: Why are atomic masses not whole numbers?
A: Atomic masses account for the natural abundance of isotopes. For example, hydrogen includes deuterium (²H) in its average atomic mass.

Q3: How accurate are these calculations?
A: The calculator uses IUPAC recommended atomic weights. For precise work, use exact isotopic composition of your sample.

Q4: Can I calculate formula mass for ionic compounds?
A: Yes, the same method applies to ionic compounds (called formula mass rather than molecular mass).

Q5: Where can I find atomic mass values?
A: Standard atomic weights are published by IUPAC and available in periodic tables.