Đáp án + Giải thích các bước giải:
$Na \xrightarrow{\text{ }(1)\text{ }} Na_{2}O \xrightarrow{\text{ }(2)\text{ }} NaOH \xrightarrow{\text{ }(3)\text{ }} NaCl \xrightarrow{\text{ }(4)\text{ }} NaOH \xrightarrow{\text{ }(5)\text{ }}Na_{2}SO_{4}$
$(1): 4Na + O_{2} → 2Na_{2}O$
$(2): Na_{2}O + H_{2}O → 2NaOH$
$(3): 2NaOH + CuCl_{2} → 2NaCl + Cu(OH)_{2}↓$
$(4): 2NaCl + 2H_{2}O \xrightarrow[c.m.n]{đpdd} 2NaOH + Cl_{2}↑ + H_{2}↑$
$(5): 2NaOH + FeSO_{4} → Na_{2}SO_{4} + Fe(OH)_{2}↓$
