vi khong lam mat mau ddBr2 =>no hoac nhan thom khong co chuc andehitH phai la so chan nen C6H4(COOH)2nhom chuc nam o vi tri 1,2&1,3
b.2
tao CO2 nen la axit co mot lien ket pi
C3H5COOH
C=C-C-COOH
C=C(C)-COOH
C-C=C-COOH
neu dung cho mot binh chon dung nha