Question

Low concentrations of hydrogen sulfide in air react with silver to form Ag₂S, more familiar to us as tarnish. Silver polish contains alumium metal powder as an alkaline suspension.

Write a balanced net ionic equation for the redox reaction of Ag₂S and Al metal that produces Ag metal and Al(Oh)₃

Answer 1

The net ionic equation for the reaction that restores tarnished silver using aluminum metal is 3 Ag2S(s) + 2 Al(s) → 6 Ag(s) + Al2O3(s) + 3 S(s). Aluminum is oxidized, while silver sulfide is reduced, reversing the tarnishing process.

Step-by-step explanation:

The balanced net ionic equation for the redox reaction between silver sulfide (Ag2S) and aluminum metal (Al) that produces silver metal (Ag) and aluminum hydroxide (Al(OH)3) is as follows:

3 Ag2S(s) + 2 Al(s) → 6 Ag(s) + Al2O3(s) + 3 S(s)

Note that aluminum hydroxide is not directly formed in this reaction; instead, aluminum oxide (Al2O3 (s)) is produced which can react with water to form aluminum hydroxide.

Aluminum (Al) serves as the reducing agent in this reaction, reducing silver sulfide back to elemental silver. Simultaneously, the Al becomes oxidized, and with its strong affinity for oxygen, forms aluminum oxide. The reaction essentially reverses the tarnishing of silver by removing sulfur and restoring the silver surface.