a.

Na2O+H2O→2NaOH

SO2+H2O⇄H2SO3

P2O5+3H2O→2H3PO4

b.

CuO+2HCl→CuCl2+H2O

Fe2O3+6HCl→2FeCl3+3H2O

Na2O+2HCl→2NaCl+H2O

2P2O5+3HCl→POCl3+3HPO3

MgO+2HCl→MgCl2+H2O

Al2O3+6HCl→2AlCl3+3H2O

c.

SO2+2KOH→K2SO3+H2O

Al2O3+2KOH→2KAlO2+H2O

---------------------Nguyễn Hoạt------------------

Em tham khảo nha:

\(\begin{array}{l}
a)\,N{a_2}O,S{O_2},{P_2}{O_5}\\
N{a_2}O + {H_2}O \to 2NaOH\\
S{O_2} + {H_2}O \to {H_2}S{O_3}\\
{P_2}{O_5} + 3{H_2}O \to 2{H_3}P{O_4}\\
b)\,CuO,F{e_2}{O_3},MgO,A{l_2}{O_3}\\
CuO + 2HCl \to CuC{l_2} + {H_2}O\\
F{e_2}{O_3} + 6HCl \to 2FeC{l_3} + 3{H_2}O\\
MgO + 2HCl \to MgC{l_2} + {H_2}O\\
A{l_2}{O_3} + 6HCl \to 2AlC{l_3} + 3{H_2}O\\
c)S{O_2},{P_2}{O_5},A{l_2}{O_3}\\
S{O_2} + 2NaOH \to N{a_2}S{O_3} + {H_2}O\\
{P_2}{O_5} + 6KOH \to 2{K_3}P{O_4} + 3{H_2}O\\
A{l_2}{O_3} + 2KOH \to 2KAl{O_2} + {H_2}O
\end{array}\)