What is the molar mass of sodium carbonate (Na2CO3)?
The correct answer and explanation is:
The molar mass of sodium carbonate (Na₂CO₃) can be calculated by adding up the molar masses of each element in the compound. Sodium carbonate consists of two sodium (Na) atoms, one carbon (C) atom, and three oxygen (O) atoms.
- Sodium (Na): The atomic mass of sodium is approximately 22.99 g/mol. Since there are two sodium atoms in sodium carbonate, the contribution from sodium is: 2×22.99=45.98 g/mol2 \times 22.99 = 45.98 \, \text{g/mol}
- Carbon (C): The atomic mass of carbon is approximately 12.01 g/mol. Since there is only one carbon atom in sodium carbonate, the contribution from carbon is: 1×12.01=12.01 g/mol1 \times 12.01 = 12.01 \, \text{g/mol}
- Oxygen (O): The atomic mass of oxygen is approximately 16.00 g/mol. Since there are three oxygen atoms in sodium carbonate, the contribution from oxygen is: 3×16.00=48.00 g/mol3 \times 16.00 = 48.00 \, \text{g/mol}
Now, add these contributions together to find the molar mass of sodium carbonate: 45.98 g/mol (Na)+12.01 g/mol (C)+48.00 g/mol (O)=106.00 g/mol45.98 \, \text{g/mol (Na)} + 12.01 \, \text{g/mol (C)} + 48.00 \, \text{g/mol (O)} = 106.00 \, \text{g/mol}
Thus, the molar mass of sodium carbonate (Na₂CO₃) is 106.00 g/mol.
Explanation
To calculate the molar mass, it is necessary to consider the atomic masses of each element in the compound. These atomic masses are derived from the periodic table and represent the mass of one mole of each atom. For compounds, the molar mass is simply the sum of the individual atomic masses, accounting for the number of atoms of each element in the compound.
In the case of sodium carbonate, Na₂CO₃, you add up the contributions from sodium, carbon, and oxygen atoms to determine its total molar mass. This information is crucial when performing stoichiometric calculations or determining the amount of a substance involved in a chemical reaction.