The mass of calcium carbonate that is needed to produce 47.0 l of Co2 at STP is 209.8 grams
calculation
CaCO₃ (s) → CaO(s) +Co₂
calculate the moles CO2 at STP
AT STP 1 mole of gas = 22.4 L
? moles = 47.0 L
by cross multiplication
=[ (1 moles x 47.0 l) / 22.4 L] =2.098 moles
use of mole ratio to calculate the moles of CaCO₃
CaCo₃:Co₂ is 1:1 therefore the moles of CaCo₃ is also = 2.098 moles
mass = moles x molar mass
The molar mass of CaCo₃ = 40 +12 +(16 x3) =100 g/mol
mass =2.098 moles x 100 g/mol =209.8 grams