Molar Mass Calculation

Calculating Molar Mass

Example: Calculating the Molar Mass of Carbon Dioxide (CO₂)

Step 1: Identify the Elements in the Compound

Carbon dioxide consists of carbon (C) and oxygen (O).

Step 2: Find the Atomic Mass of Each Element

You can find the atomic mass of each element on the periodic table:

• Atomic mass of carbon (C) ≈ 12.01 g/mol
• Atomic mass of oxygen (O) ≈ 16.00 g/mol

Step 3: Determine the Number of Each Type of Atom in the Compound

In one molecule of carbon dioxide (CO₂):

• There is 1 carbon atom.
• There are 2 oxygen atoms.

Step 4: Calculate the Molar Mass of the Compound

The molar mass of a compound is the sum of the molar masses of its constituent elements, taking into account the number of each type of atom in the compound.

For carbon dioxide (CO₂):

Molar mass of CO₂ = (1×12.01 g/mol) + (2×16.00 g/mol) = 12.01 g/mol + 32.00 g/mol = 44.01 g/mol

Conclusion

The molar mass of carbon dioxide (CO₂) is 44.01 g/mol. This means that one mole of CO₂ has a mass of 44.01 grams.