дано
m(C2H4) = 5 g
m(C2H6)-?
C2H4+H2-->C2H6
M(C2H4) = 28 g/mol
n(C2H4) = m/M = 5/ 28 = 0.18 mol
n(C2H4) = n(C2H6) = 0.18 mol
M(C2H6) = 30 g/mol
m(C2H6) = n*M = 0.18 * 30 = 5.4 g
ответ 5.4 г
