... m CO2 m H2O 64,54(g) - t m gam X thu c 32, 27 gam CO v H2O thỡ m X 32, 27 27 , 62 13,81(g) 64,54 Cõu 38: Chn C - Cho m gam Cu v Fe tỏc dng vi HNO v H2SO4 thỡ n NO n HCl 2n H2SO4 0 ,2 mol - Hn... mol, n H2O n X 0,09 mol n CH2 n AlaNa 3n ValNa 0,31 mol Vy n Y m X 57n C H3ON 14n CH2 18n H2 O 27 , 62 (g) - t X thỡ n CO2 2n C 2H3ON n CH2 1,07 mol n H2O 1,5n C 2H3ON n CH2 0,97... ca m l A 20 gam B 24 gam C 23 gam D 28 gam Cõu 39: Cho ba phng trỡnh ion (1) Cu2+ + Fe Cu + Fe2+ (2) Cu + 2Fe3+ Cu2+ + 2Fe2+ (3) Fe2+ + Mg Fe + Mg2+ Nhn xột ỳng l ? A Tớnh kh: Mg > Fe2+ > Cu