Question

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

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

Answer 1

The balanced net ionic equation for the redox reaction between Ag₂S and Al to produce Ag and Al(OH)₃ involves balancing the reduction half-reaction of Ag₂S to Ag and the oxidation half-reaction of Al to Al(OH)₃, ensuring the number of electrons lost equals the number gained.

Step-by-step explanation:

To find the balanced net ionic equation for the redox reaction between Ag2S and Al metal, we need to separate the reactions into their half-reactions. The silver sulfide (Ag2S) is reduced to silver (Ag), and aluminum (Al) is oxidized to aluminum hydroxide (Al(OH)3). The half-reactions are as follows:

• 
  
• Ag2S + 2e- → 2Ag + S2- (Reduction)
• 
  
• 2Al + 6H2O → 2Al(OH)3 + 6e- (Oxidation)

To balance the electrons, we need to multiply the number of electrons lost in the oxidation by the number needed for the reduction of Ag2S, resulting in:

• 
  
• 3(Ag2S + 2e- → 2Ag + S2-)
• 
  
• 2Al + 6H2O → 2Al(OH)3 + 6e-

Combining and balancing these equations gives us the net ionic equation:

• 
  
• 3Ag2S + 6e- → 6Ag + 3S2-
• 
  
• 2Al + 6H2O → 2Al(OH)3 + 6e-
• 
  
• 3Ag2S + 2Al + 6H2O → 6Ag + 2Al(OH)3 + 3S2-