Multiple choice

The chemical reagent used for leaching of gold and silver ores is

  1. sodium hydroxide

  2. potassium cyanide

  3. sodium thiosulphate

  4. sodium bicarbonate

  5. none of these

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This option is correct because the leaching of gold means gold cyanidation of gold and for silver ores cyanidation of silver. Potassium cyanide (KCN) is used for extraction of gold and silver with respect to water to form soluble coordination complexes (K[Ag(CN)2], K[Au(CN)2]).