If you have 1.00 gram of Na2CO3, how many moles of Na2CO3 is that?
The Correct Answer and Explanation is :
To find out how many moles are in 1.00 gram of sodium carbonate (Na₂CO₃), we first need to determine the molar mass of Na₂CO₃.
Step 1: Calculate the Molar Mass
Sodium carbonate is composed of:
- 2 Sodium (Na) atoms
- 1 Carbon (C) atom
- 3 Oxygen (O) atoms
Using the atomic masses (approximately):
- Sodium (Na): 22.99 g/mol
- Carbon (C): 12.01 g/mol
- Oxygen (O): 16.00 g/mol
The molar mass of Na₂CO₃ can be calculated as follows:
[
\text{Molar mass of Na}_2\text{CO}_3 = (2 \times \text{Na}) + (1 \times \text{C}) + (3 \times \text{O})
]
[
= (2 \times 22.99 \, \text{g/mol}) + (1 \times 12.01 \, \text{g/mol}) + (3 \times 16.00 \, \text{g/mol})
]
[
= 45.98 \, \text{g/mol} + 12.01 \, \text{g/mol} + 48.00 \, \text{g/mol}
]
[
= 105.99 \, \text{g/mol}
]
Step 2: Calculate Moles
Now that we have the molar mass of Na₂CO₃, we can calculate the number of moles in 1.00 gram of Na₂CO₃ using the formula:
[
\text{Moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}
]
Substituting the known values:
[
\text{Moles} = \frac{1.00 \, \text{g}}{105.99 \, \text{g/mol}} \approx 0.00943 \, \text{mol}
]
Conclusion
Thus, 1.00 gram of sodium carbonate (Na₂CO₃) is approximately 0.00943 moles. This calculation demonstrates how to convert mass into moles using the molar mass, a fundamental concept in chemistry that allows scientists to quantify substances in chemical reactions accurately. Understanding moles is crucial for stoichiometry, the branch of chemistry that deals with the quantities of reactants and products in chemical reactions, facilitating the precise formulation of reactions and compounds in both laboratory and industrial settings.