A.CH3CHO+2Cu(OH)2
CH3COOH+Cu2O↓+2H2O
B.CH3CHO+2Ag(NH3)2OH
CH3COONH4+2Ag↓+3NH3+H2O
C.CH3CHO+H2
CH3CH2OH
D.CH3CHO+CuO
CH3COOH+Cu
A.CH3CHO+2Cu(OH)2
CH3COOH+Cu2O↓+2H2O
B.CH3CHO+2Ag(NH3)2OH
CH3COONH4+2Ag↓+3NH3+H2O
C.CH3CHO+H2
CH3CH2OH
D.CH3CHO+CuO
CH3COOH+Cu
C
解析:A、B、D三个反应中,CH3CHO都是被氧化,发生氧化反应,而C反应中CH3CHO则是被还原,发生还原反应。