Дано
m гряз(C3H8) = 50 g
W(прим) = 2%
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V(CO2)-?
m чист (C3H8) = 50-(50*2%/100%) = 49 g
C3H8+5O2-->3CO2+4H2O
M(C3H8) = 44 g/mol
n(C3H8) = m/M = 49/44 = 1.11 mol
n(C3H8) = 3n(CO2)
n(CO2) = 3*1.11 = 3.33 mol
V(CO2) = n*Vm = 3.33*22.4 = 74.6 L
ответ 74.6 л