Trong phương pháp thủy luyện dùng để điều chế Ag từ quặng có chứa Ag2S. Hóa chất cần dùng là:

* Hướng dẫn giải

Phương trình điều chế Ag từ Ag2S bằng phương pháp thủy luyện

$A{g}_{2}S+4NaCN\to 2Na\left[Ag{\left(CN\right)}_2\right]+N{a}_{2}S$$\mathrm{<span\; style="color:\#000000;">A</span>}{\mathrm{<span\; style="color:\#000000;">g</span>}}_{\mathrm{<span\; style="color:\#000000;">2</span>}}\mathrm{<span\; style="color:\#000000;">S</span>}<span\; style="color:\#000000;">+</span>\mathrm{<span\; style="color:\#000000;">4</span>}\mathrm{<span\; style="color:\#000000;">N</span>}\mathrm{<span\; style="color:\#000000;">a</span>}\mathrm{<span\; style="color:\#000000;">C</span>}\mathrm{<span\; style="color:\#000000;">N</span>}<span\; style="color:\#000000;">\to </span>\mathrm{<span\; style="color:\#000000;">2</span>}\mathrm{<span\; style="color:\#000000;">N</span>}\mathrm{<span\; style="color:\#000000;">a</span>}<span\; style="color:\#000000;">[</span>\mathrm{<span\; style="color:\#000000;">A</span>}\mathrm{<span\; style="color:\#000000;">g</span>}{<span\; style="color:\#000000;">(</span>\mathrm{<span\; style="color:\#000000;">C</span>}\mathrm{<span\; style="color:\#000000;">N</span>}<span\; style="color:\#000000;">)</span>}_{\mathrm{<span\; style="color:\#000000;">2</span>}}<span\; style="color:\#000000;">]</span><span\; style="color:\#000000;">+</span>\mathrm{<span\; style="color:\#000000;">N</span>}{\mathrm{<span\; style="color:\#000000;">a</span>}}_{\mathrm{<span\; style="color:\#000000;">2</span>}}\mathrm{<span\; style="color:\#000000;">S</span>}$

$Zn+2Na\left[Ag{\left(CN\right)}_2\right]\to N{a}_2\left[Zn{\left(CN\right)}_4\right]+2Ag$