Final answer:
To find the number of molecules in 450 g of oxygen, calculate the moles of O2 by dividing the mass by the molar mass and then multiply the moles by Avogadro's number, resulting in approximately 8.468 × 1024 molecules.
Step-by-step explanation:
The student asked about the number of molecules in 450 g of oxygen. To answer this, we first need to know the molar mass of oxygen, which is 32.00 g/mol for O2. Using Avogadro's number, which is 6.022 × 1023 molecules per mole, we can calculate the moles of oxygen in 450 g, and subsequently, the number of oxygen molecules.
First, divide the mass of oxygen by its molar mass to get the number of moles:
450 g O2 / 32.00 g/mol = 14.0625 mol O2
Next, multiply the number of moles by Avogadro's number to find the number of molecules:
14.0625 mol O2 × 6.022 × 1023 molecules/mol = 8.468 × 1024
molecules of oxygen.