Chapter 21, Problem 21.36SP

Interpretation Introduction

Interpretation:

Using the reduction potentials provided for each metal, explain why certain metals would be more likely to produce an oxide during roasting while others provide elemental metals. Predict whether CdS will form an oxide or elemental Cd after roasting.

Concept introduction:

• An ore is a complex mixture of metal-containing mineral and economically worthless material called gangue, consisting of sand, clay, and other impurities.
• Extracting a metal from its ore requires three main steps: (1) concentration of the ore, and if necessary, chemical treatment prior to reduction; (2) reduction of the mineral to the free metal; (3) refining or purification of the metal.
• Roasting is the process of heating the sulfide minerals in air (O₂) to form metal-oxides

To classify:Why some metal sulfides produce metal oxides or elemental metal during roasting and predict the product of roasting CdS.