the reaction is : C3H8 + 5O2 ===> 3CO2 + 4H2O
find the number of moles of H2O using the molar mass of H2O
moles of H2O = 75g/18.02 g/mol = 4.162 moles
go between the H2O and the propane to find the mole of propane
4.162 moles H2O its a 1 : 4 ratio so divide 4.162 / 4 = 1.041mol of propane
use this equation to find the volume of gas required : V = nRT/P
n is the moles of gas (propane)
R is the universal gas constant (0.082057338)
T is the temperature of the gas (273K)
V = (1.041) x (0.08206 L-atm/mol-K) x (273K)/(1 atm)
V = 23.3 L of C3H8
hope that helps
