Step-by-step explanation:
To convert from grams to moles we have to use the molar mass. Let's calculate the molar mass of Cr₂O₃.
molar mass of Cr = 52.00 g/mol
molar mass of O = 16.00 g/mol
molar mass of Cr₂O₃ = 2 * 52.00 g/mol + 3 * 16.00 g/mol
molar mass of Cr₂O₃ = 152 g/mol
Once we know the molar mass of Cr₂O₃ we can find the number of moles present in 600 g of it.
mass of Cr₂O₃ = 600 g
number of moles of Cr₂O₃ = mass of Cr₂O₃/(molar mass of Cr₂O₃)
number of moles of Cr₂O₃ = 600 g/(152 g/mol)
number of moles of Cr₂O₃ = 3.95 moles
Answer: 3.95 moles are present in 600 g of Cr₂O₃.