дано
m прак (C2H5OH) = 23 g
η(C2H5OH) = 50%
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V(C2H4)-?
C2H4+HOH-->C2H5OH
M(C2H5OH) = 46 g/mol
m теор (C2H5OH) = 23*100% / 50% = 46 g
n(C2H5OH) = m/M = 46 / 46 = 1 mol
n(C2H5OH) = n(C2H4) = 1 mol
V(C2H4) = n*Vm = 1 * 22.4 = 22.4 L
ответ 22.4 л