theo cách 2:hỗn hợp X:H2:ymol,CnH2n+2-2k:x mol=>MX=(14n+2-2k)+2y/(x+y)=mX/(x+y)=13.4(1)
Y:CnH2n+2:x mol,H2 dư:y-kx
=>MY=mY/(x+y-kx)=33.5(2)
lấy 2:1=>(x+y)/(x+y-kx)=5/2=>x+y=5/3*kx
thay vào 1=>14n=21k=>k=2,n=3=>CTPT:C3H4
theo cách 1:CnH2n-2+2k=>nCO2
-------------n/0.3--------0.3mol
CnH2n+2-2k +kH2=>C2H2n+2
n/0.3--------n/0.3 *k =0.2
=>k/n=2/3
=>n=3,k=2=>C3H4
