Question

How many grams of Ca are there in a sample of Ca that contains the same number of moles as a 49.3 gram sample of He?

Answer 1

Mass of Ca sample = 494 g       (exact mass = 493.64 g)

Explanation

Mass He = 49.3 g

moles He = (mass He) / (molar mass He)

moles He = (49.3 g) / (4.0026 g/mol)

moles He = 12.317 mol

moles Ca = moles He

moles Ca = 12.317 mol

mass Ca = (moles Ca) * (molar mass Ca)

mass Ca = (12.317 mol) * (40.0780 g/mol)

mass Ca = 493.64 g