Question

To figure out a "mole" of something, you determine the molecular mass. What is the molecular mass (or molecular weight) of calcium carbonate (CaCO₃)?

a) 68 grams/mole.
b) 100 grams/mole.
c) 124 grams/mole.
d) 52 grams/mole.

Answer 1

The molecular mass of calcium carbonate (CaCO3) is found by adding the molar masses of calcium, carbon, and three oxygen atoms, resulting in 100.09 g/mol. The closest answer choice is b) 100 grams/mole.

Step-by-step explanation:

To calculate the molecular mass (or molecular weight) of calcium carbonate (CaCO3), you need to sum the molar masses of each constituent element, taking into account the number of atoms of each element within the compound.

• Calcium (Ca): 40.08 g/mol
• Carbon (C): 12.01 g/mol
• Oxygen (O): 16.00 g/mol × 3 atoms = 48.00 g/mol

Add these values together to get the molecular mass of CaCO3:

40.08 g/mol (for Ca) + 12.01 g/mol (for C) + 48.00 g/mol (for O) = 100.09 g/mol

Therefore, the closest answer to the provided options would be b) 100 grams/mole.