Is it that if I want to renew my Gold Jewellery through in Electrolysis, the Weight will INCREASE, and through Aqua Regia, the weight will REDUCE?
Dear student,
Electrorefining of gold produces a high amount of pure gold from the impure sample but it will not generate the gold. It is a kind of extraction method where pure gold is extracted from impure gold. The electrolytic refining process for gold uses hydrochloric acid as the electrolyte. The anode is made of gold alloy and the cathode is usually a thin sheet of high purity gold. The electric current ionizes the electrolyte and transfers dissolved gold from the anode to the cathode, thereby increasing the purity of the gold at the cathode.
Regards
Electrorefining of gold produces a high amount of pure gold from the impure sample but it will not generate the gold. It is a kind of extraction method where pure gold is extracted from impure gold. The electrolytic refining process for gold uses hydrochloric acid as the electrolyte. The anode is made of gold alloy and the cathode is usually a thin sheet of high purity gold. The electric current ionizes the electrolyte and transfers dissolved gold from the anode to the cathode, thereby increasing the purity of the gold at the cathode.
Aqua regia is a very strong acid and consists of nitric acid and hydrochloric acid in a ratio of 1:3. It dissolves gold and Platinum by forming Gold chloride and chloroplatinate ion as shown below:
Au (s) + 3NO3 -(aq) + 6H+(aq) + 4Cl-(aq) → AuCl4 - (aq) + 3NO2 (g) + 3H2O (l)
Pt (s) + 4NO3 -(aq) + 8H+(aq) + 6Cl-(aq) → PtCl6 -2 (aq) + 4NO2 (g) + 4H2O (l)
Due to this, more and more gold is oxidized. Thus, gold dissolves to become chloroauric acid (HAuCl4).Regards