The ideal gas law
PV=nRT
relates pressure P, volume V, temperature T, and number of moles of a gas, n. The gas constant R equals 0.08206 L⋅atm/(K⋅mol) or 8.3145 J/(K⋅mol). The equation can be rearranged as follows to solve for n :n=PVRT
This equation is useful when dealing with gaseous reactions because stoichiometric calculations involve mole ratios.

Part A
When heated, calcium carbonate decomposes to yield calcium oxide and carbon dioxide gas via the reaction CaCO3(s)→CaO(s)+CO2(g)
What is the mass of calcium carbonate needed to produce 31.0 L
of carbon dioxide at STP?
Express your answer with the appropriate units.

Butane, C4H10
, is a component of natural gas that is used as fuel for cigarette lighters. The balanced equation of the complete combustion of butane is

2C4H10(g)+13O2(g)→8CO2(g)+10H2O(l)


At 1.00 atm and 23 ∘C , what is the volume of carbon dioxide formed by the combustion of 4.00g of butane? Express your answer with the appropriate units.