How is the molar mass of SO3 determined using atomic weights?

• Sulfur trioxide is composed of one sulfur atom (S) and three oxygen atoms (O).

2. Atomic Weights:

• The atomic weight of sulfur is approximately 32.07 g/mol.
• The atomic weight of oxygen is approximately 16.00 g/mol.

3. Calculation:

Multiply the atomic weight of sulfur by the number of sulfur atoms:

1×32.07g/mol=32.07g/mol.

4. Multiply the atomic weight of oxygen by the number of oxygen atoms:

3×16.00g/mol=48.00g/mol.

5. Summation:

Add the contributions from sulfur and oxygen to get the total molar mass:

32.07g/mol+48.00g/mol=80.07g/mol.

6. Result:

The molar mass of SO₃ is therefore 80.06 g/mol, which is the sum of the atomic weights of its constituent atoms.

Understanding the molar mass of a compound like sulfur trioxide is crucial for stoichiometric calculations in chemical reactions, allowing chemists to predict yields and reactant consumption.

It also plays a role in determining the physical properties of the substance, such as density and vapor pressure.