PbS + H2O2 - > PbSO4 + H2O

[Vriska]

I don't get it, how did the sulfur get an oxygen, I'm unable to find any any half reaction wherein a oxygen ion is generated. So what is happening here?

 

[Borek]

You can oxidize sulfides just by roasting them in the air, there is no solution, no ions there at all. Why do you think you need "oxygen ions" for anything?

 

[Vriska]

You can oxidize sulfides just by roasting them in the air, there is no solution, no ions there at all. Why do you think you need "oxygen ions" for anything?

Idea was that you'd need electrons first from PbS to start the reaction. you'd have some PbS -> PbS(2+) + 2e. Now you could have H2O2 accept electrons as an oxidising agent. But nowhere I'm seeing any half reaction that could put an oxygen there and plug that +2 charge.

But now you put it that way, it looks like simple burning. But why is acidic medium required there then? what if bubble carbon monoxide through hydrogen peroxide can I expect CO2, will this be as exothermic as burning CO?

 

[Borek]

But why is acidic medium required there then?

What do you know about solubility of sulfides? Can you think about a way of shifting the dissolution to the right?

 

[Vriska]

What do you know about solubility of sulfides? Can you think about a way of shifting the dissolution to the right?

I'm unafraid i don't follow, PbS is apparently quite insoluble in water. I'm not sure how acid will help unless there's an hydroxide on the right side which will be eaten by the acid.

 

[Borek]

What about protonating S^2-?

 

[Vriska]

What about protonating S^2-?

Woah, amazing. thank you!

 

[Vriska]

What about protonating S^2-?

Heyyyyy wait a second what does dissolution have to do with this reaction?

 

[Borek]

Reactions in the liquid phase are much faster.