JEE Main202227 Jun 2022Evening ShiftChemistryGeneral Principles and Processes of Isolation of MetalsActual
Statement I: Leaching of gold with cyanide ion in absence of air / O 2 leads to cyano complex of Au (III). Statement II: Zinc is oxidized during the displacement reaction carried out for gold extraction. In the light of the above statements, choose the correct answer from the options given below.
Options
- ABoth Statement 1 and statement 2 are correct
- BBoth Statement 1 and statement 2 are incorrect
- CStatement 1 is correct but statement 2 is incorrect
- DStatement 1 is incorrect but statement 2 is correct
Correct answer
D. Statement 1 is incorrect but statement 2 is correct
Step-by-step solution
4   Au s + 8 CN - aq + 2 H 2 O aq + O 2 g → 4 Au CN 2 - aq + 4 OH - aq The oxidation state of gold in the complex is +1. 2 Au CN 2 - aq + Zn s → 2 Au s + Zn CN 4 2 - aq The oxidation state of zinc in the complex is +2. Oxidation state of Zn in Zn CN 4 2 - +2. As, Oxidation state of zinc is converted from zero(elemental state) to +2.It is undergoing oxidation. Hence,Statement 1 is incorrect but statement 2 is correct