... oxalic B axit acrylic C axit aipic D axit fomic Cõu 20: Thy phõn ht m gam tetrapeptit Ala-Ala-Ala-Ala (mch h) thu c hn hp gm 28,48 gam Ala, 32 gam Ala-Ala v 27,72 gam Ala-Ala-Ala Giỏ tr ca m l A 81,54 ... ta X l A 3,94 gam B 7,88 gam C 11,28 gam D 9,85 gam Cõu 40: Cho dóy cỏc hp cht thm: p-HO-CH2-C6H4-OH, p-HO-C6H4-COOC2H5, p-HO-C6H4-COOH, p-HCOO-C6H4-OH, p-CH3O-C6H4-OH Cú bao nhiờu cht dóy tha ... tạo): A1 Br2, Fe A2 dd HCl A5 dd HCl o A4 Toluen Br2, askt dd NaOH đặc, d, to cao, p cao A7 dd NaOH đặc, d, t cao, p cao o dd NaOH, t A8 o CuO, t A3 A6 o A9 Ag2O/NH3, t A1 0 Biết A1 , A4 , A7 chất...