Question

What is the number of molecules in 32 G of oxygen?

Answer 1

To determine the number of molecules in a given mass of a substance, you can use the concept of molar mass and Avogadro's number.

1. Calculate the molar mass of oxygen (O₂). Oxygen has an atomic mass of approximately 16 g/mol.

2. Determine the number of moles in the given mass of oxygen by dividing the mass by the molar mass.

   Number of moles = Mass (g) / Molar mass (g/mol)

   In this case: Number of moles = 32 g / 16 g/mol = 2 mol

3. Apply Avogadro's number, which is approximately 6.022 × 10²³ molecules/mol, to calculate the number of molecules.

   Number of molecules = Number of moles × Avogadro's number

   Number of molecules = 2 mol × (6.022 × 10²³ molecules/mol) = 1.2044 × 10²⁴ molecules

Therefore, there are approximately 1.2044 × 10²⁴ molecules in 32 g of oxygen.