sulfate reducing bacteria equations (1 Viewer)

[pqd]

From what I have seen, there are two equations describing the reduction of sulfate:
SO₄^2- + 10H⁺ + 8e^---> H₂S + 4H₂O
SO₄^2- + 5H₂O + 8e^---> HS^- + 9OH^-

My guesses as to why this is are either:
1. the first equation occurs in acidic conditions hence the H ions but the second occurs under more neutral conditions
2. the equations are equivalent in terms of what actually happens and some atoms are omitted

Can someone please clarify and if they are equivalent, can someone show me how

 

[mjrow]

That is only the first equation. You need to include the oxidation of the artefact (eg. iron) and then combine the two to show the production of more H ions. (I use the first equation)

 

[Queenroot]

From what I have seen, there are two equations describing the reduction of sulfate:
SO₄^2- + 10H⁺ + 8e^---> H₂S + 4H₂O
SO₄^2- + 5H₂O + 8e^---> HS^- + 9OH^-

My guesses as to why this is are either:
1. the first equation occurs in acidic conditions hence the H ions but the second occurs under more neutral conditions
2. the equations are equivalent in terms of what actually happens and some atoms are omitted

Can someone please clarify and if they are equivalent, can someone show me how

Don't use the second one

 

[andrew29223]

Don't use the second one

Why shouldn't we use the second one? It has been used in HSC answers before?

 

[Queenroot]

Why shouldn't we use the second one? It has been used in HSC answers before?

Anaerobic acidic conditions only.
The second one produces too much base.

 

[strawberrye]

The two equations are NOT equivalent, they refer to sulphate-reducing bacteria reaction under different conditions.