Chemistry Forum

Hello.

I had an exam yesterday and this is the question that I dont know if a answerd right:

* Balance the reaction where 1.07g/L ethanol oxidize to acetic acid and CO₂?
* Then calculate the pH assuming that ethanol oxidaze only to acetic acid? I think that pKa was 4.76
* How will the pH change if we have more ethanol

What was your answers. You show only the questions?

my answer was:

2C₂H₆O + 4O₂ = C₂H₄O₂ + 2CO₂ + 4H₂O

Since 2 EtOh give 1 acetic acid, I divided the concentration of EtOh by 2 to get the conc. of acetic acid = 0.0116 mol/L, and then calculated pH:

pH=1/2 pKa - 1/2 log (HA)
pH=1/2 4,76 - 1/2 log (0.0116)
pH= 3.27

Sounds good.