Question

The electrolytes usually used in the electroplating of gold and silver, respectively, are :
(A) [Au(CN₂]⁻ and [Ag(CN)₂]⁻ (B) [Au(Cn)₂]⁻ and [AgCl₂]⁻ (C) [Au(OH)₄]⁻ and [Ag(OH)₂]⁻ (D) [Au(NH₃)₂]⁺ and [Ag(CN)₂]⁻

Answer 1

Answer:

Most plating of gold and its alloys is carried out from solutions containing gold as a soluble cyanide complex. Gold reacts with alkali cyanides to form either monovalent (MAu(CN)2) or trivalent (MAu(CN)4) complexes, wherein M is an alkali metal or, in some cases, ammonium ion.