Which conversion factor should you use to convert moles of sodium (Na) to the mass of sodium?

• A. The molar mass of Na (22.99 g/mol)
• B. The atomic number of Na (11)
• C. The density of Na (0.97 g/cm^3)
• D. Avogadro's number (6.022 × 10^{23} atoms/mol)

Answer: (A)

Verified step by step guidance

1. Understand that to convert from moles of an element to its mass, you need a conversion factor that relates moles to grams.
2. Recall that the molar mass of an element, expressed in grams per mole (g/mol), tells you how many grams are in one mole of that element.
3. Identify the molar mass of sodium (Na), which is approximately 22.99 g/mol; this means 1 mole of Na has a mass of 22.99 grams.
4. Recognize that other options like atomic number, density, or Avogadro's number do not directly convert moles to mass: atomic number is the number of protons, density relates mass and volume, and Avogadro's number relates moles to number of particles.
5. Therefore, the correct conversion factor to convert moles of sodium to mass is the molar mass of sodium, 22.99 g/mol.