Решение:
m(CxHyOz) = 100
m(C.) = m(CxHyOz)* w(C.)/100
m(H) = m(CxHyOz)* w(H)/100
m(O) = m(CxHyOz)* w(O)/100
m(C.)= 72.96
m(H)= 5.44
m(O)= 21.6
2) N(C.)= m(C.)/ Ar(C.)
N(H)= m(H)/ Ar(H)
N(O)= m(O)/ Ar(O)
N(C.) = 6.08
N(H) = 5.44
N(O) = 1.35
3) N(C.): N(H): N(O) = x:y:z
x:y:z = 6.08 : 5,44 : 1,35
x:у:z = 4.5 : 4 : 1
=> 9:8:2
=> C9H8O2(M = 148г/моль)
Рh-CH=CH-COOH, где Ph - С6Н5