Chemistry stoichiometry

Question

Calculate the theoretical mass of calcium carbonate using the sodium carbonate as starting material with 1.3 grams

Answer 1

Not entirely sure what you are doing because it sounds like you are starting with sodium carbonate and making calcium carbonate. If that's actually the case, I'll answer it based on that, but that doesn't make a of sense. Having said that...

1.3 g Na₂CO₃ x 1 mole Na₂CO₃^2- /106 g = 0.012 moles

0.012 moles Na₂CO₃ x 1 mole CO₃/mole Na₂CO₃ = 0.012 moles CO₃^2-

Theoretical mass of CaCO₃ = 0.012 moles CO₃ x 100 g CaCO₃/mole = 1.2 g CaCO₃