Final answer:
To determine the quantity of pure CaCl₂ in 7.5 g of CaCl₂•9H₂O, we need to calculate the quantity (in moles) of CaCl₂•9H₂O and then use the molar ratio to determine the quantity of pure CaCl₂. Finally, we can convert the quantity of pure CaCl₂ from moles to grams.
Step-by-step explanation:
To determine the quantity of pure CaCl₂ in 7.5 g of CaCl₂•9H₂O, we need to consider the molar mass of CaCl₂ and the molar mass of CaCl₂•9H₂O. The molar mass of CaCl₂ is 110.98 g/mol, while the molar mass of CaCl₂•9H₂O is 219.08 g/mol. To calculate the quantity of pure CaCl₂, we need to first calculate the quantity (in moles) of CaCl₂•9H₂O. This can be done by dividing the mass of CaCl₂•9H₂O by the molar mass of CaCl₂•9H₂O.
Quantity (moles) of CaCl₂•9H₂O = mass (g) / molar mass (g/mol)
Once we have the quantity of CaCl₂•9H₂O in moles, we can multiply it by the molar ratio between CaCl₂ and CaCl₂•9H₂O to calculate the quantity of pure CaCl₂.
Quantity (moles) of CaCl₂ = Quantity (moles) of CaCl₂•9H₂O x molar ratio
Finally, we can convert the quantity of pure CaCl₂ from moles to grams by multiplying it by the molar mass of CaCl₂.
Quantity (g) of pure CaCl₂ = Quantity (moles) of CaCl₂ x molar mass (g/mol) of CaCl₂