Reacting OH- with CO2 in a Buffer Solution: Which Molecule Takes Priority?

[semc]

Here's the buffer solution H2O + CO2 <=> HCO3- + H+ so the question is why when OH- is added to the solution it reacts with CO2 to get HCO3- and H+ how do you know which one will OH- react with?Why doesn't the OH- react with the H+

 

[Borek]

Are you telling that reaction that takes place is

CO₂ + OH^- <-> HCO₃^- + H⁺

It can't be balanced (which usually means that such reaction doesn't take place).

 

[semc]

So what happen when OH- is added to the buffer?

 

[GCT]

It should react with the predominant acid in the solution.

 

[semc]

ermz...so how do you know which one is the acid?I mean in cases where the acid and base is not so obvious?

 

[Borek]

In general you may safely assume that OH^- always reacts with H⁺. That in turn may move equilibrium of other reactions (acid/base dissociations) according to the LeChatelier's principle.