1. What is Molecular Weight?

Molecular weight (molecular mass) is the sum of the atomic weights of all atoms in a molecule. For elements like sodium that exist as single atoms, the molecular weight is the same as the atomic weight.

2. Sodium (Na) Atomic Weight

Sodium is a chemical element with atomic number 11 and standard atomic weight of 22.98976928(2) u. For most calculations, we use the rounded value of 22.99 g/mol.

3. Calculation Formula

The formula to calculate molecular weight is:

For sodium:

• Atomic weight = 22.99 g/mol
• 1 mole of sodium = 22.99 grams
• 0.5 moles of sodium = 11.495 grams

4. Using the Calculator

Instructions: Enter the quantity of sodium in moles to calculate the corresponding molecular weight in grams.

5. Frequently Asked Questions (FAQ)

Q1: Why is sodium's atomic weight 22.99 and not a whole number?
A: Atomic weights account for the natural abundance of isotopes. Sodium has stable isotope Na-23 (100%) and trace amounts of Na-22.

Q2: How does this differ from molar mass?
A: For elements, molecular weight and molar mass are numerically identical but have different units (g/mol vs. g).

Q3: Can I calculate weight for sodium compounds?
A: This calculator is for elemental sodium only. For compounds like NaCl, you'd need to sum the atomic weights of all atoms.

Q4: Why is the result in grams if it's molecular weight?
A: The calculator converts moles to grams using the atomic weight. Molecular weight itself is in g/mol.

Q5: How precise is this calculation?
A: It uses the standard atomic weight of 22.99 g/mol. For ultra-precise work, use more decimal places (22.989769).