posted by George .
When heated, calcium carbonate decomposes to yield calcium oxide and carbon dioxide gas. How many grams of calcium carbonate are needed to produce 81.0 of carbon dioxide at STP?
Is the asnwer 80.95
The reaction is
CaCO3 -> CaO + CO2
What are the units of your 81.0? Liters? Whatever it is, convert it to moles at STP.
81.0 l is 3.61 moles at STP. You will need the same number of moles of CaCO3.
1 mole of CaCO3 has a mass of 40 + 12 + 48 = 100 g
80.95 g is not the answer.