Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

3.42 moles of CaO are equivalent to how many grams of CaO?

1. 64 g CaO

2. 80 g CaO

3. 192 g CaO

4. 150 g CaO

The correct answer is: 192 g CaO

To determine the mass of calcium oxide (CaO) in grams when given a specific number of moles, you can use the molar mass of CaO. The molar mass is calculated by adding the atomic weights of calcium (Ca) and oxygen (O). Calcium has an atomic mass of approximately 40.08 g/mol, and oxygen has an atomic mass of about 16.00 g/mol. Therefore, the molar mass of CaO is: \[ 40.08 \, \text{g/mol (Ca)} + 16.00 \, \text{g/mol (O)} = 56.08 \, \text{g/mol (CaO)} \] Next, to find out how many grams correspond to 3.42 moles of CaO, you multiply the number of moles by the molar mass: \[ 3.42 \, \text{moles} \times 56.08 \, \text{g/mol} = 192.00 \, \text{g} \] This calculation shows that 3.42 moles of CaO is equivalent to 192 grams. Hence, the choice that indicates 192 g of CaO