Câu 1:
1/
$M=23.2+12+16.3+18.10=286$
2/ sửa thành $C_nH_{2n+2}-x(COOH)_x$
$12n+2n+2-x+45x=14n+44x+2$
Câu 2:
1. $Na$, $Cl_2$, $H_2$, $Br_2$, $Fe$
2. $NaCl$, $HCl$, $NaOH$, $Ca(NO_3)_2$, $Fe_2(SO_4)_3$
3. Hỗn hợp $(Fe, Cu)$, $(CuCl_2, NaCl)$, $(H_2SO_4, HNO_3, HCl)$, $(AgCl, Ag_2SO_4)$, $(CO, CO_2)$