Molar Mass Calculator

How to Calculate Molar Mass

Calculating the molar mass of a chemical compound is a fundamental skill in chemistry. This calculator helps you determine the molar mass quickly and accurately.

What is the Formula?

The formula for calculating molar mass is:

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

Where:

• Atomic Mass is the mass of an atom of an element in atomic mass units (amu)
• Number of Atoms is the number of atoms of each element in the compound

What are the calculation steps?

1. Identify the elements present in the chemical formula
2. Determine the number of atoms of each element
3. Look up the atomic mass of each element from a periodic table
4. Multiply the atomic mass by the number of atoms for each element
5. Sum all the results to get the total molar mass

Example Calculation

Let's calculate the molar mass of water (H₂O):

Step 1: Identify the elements

• Hydrogen (H)
• Oxygen (O)

Step 2: Determine the number of atoms

• 2 Hydrogen atoms
• 1 Oxygen atom

Step 3: Look up atomic masses

• H: 1.008 g/mol
• O: 15.999 g/mol

Step 4: Calculate

Molar Mass of H₂O = (2 × 1.008 g/mol) + (1 × 15.999 g/mol)

= 2.016 g/mol + 15.999 g/mol

= 18.015 g/mol

Therefore, the molar mass of water (H₂O) is 18.015 g/mol.

Diagram of Molar Mass

The following diagram illustrates the concept of molar mass:

This diagram shows the molecular structure of water (H₂O) and its molar mass. The two smaller circles represent hydrogen atoms, while the larger circle represents the oxygen atom. The sum of their atomic masses gives us the molar mass of water.