When a 1.25-gram sample of limestone CaCO3 was dissolved in hydrochloric acid, 0.44 gram of CO2 was generated.?

[janaki]

If the rock contained no carbonate other than CaCO3, what was the percent of CaCO3 by mass in the limestone?

CaCO3 + 2HCl ----> CaCl2 + CO2 + H2O

[Fuzzwood]

Sure: 0.44 g of CO₂ is how many moles of CO₂? Then, what is the ratio of CaCO₃ to CO₂? And thus how many moles of CaCO₃ do I have? How many grams?