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Chemistry

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  • $\begingroup$ Check all 4 parallel ongoing equilibrium processes and they eq. constants. CO2(g) <=> CO2(aq) <=> H2CO3(aq) <=> HCO3-(aq) <=> CO3^2-(aq). All of them are reversible. $\endgroup$
    – Poutnik
    Commented Feb 5 at 21:12
  • $\begingroup$ I agree with that. From my understanding these processes are the same in carbonic acid dissolved in water as they are with sodium bicarbonate dissolved in water. And in the former case for the level of partial pressure of CO2 in ambient air the equilibrium of this system lies very strongly towards CO2(g), however for the latter case it doesn't (as we don't see effervescence). My question can be rephrased as asking why there is a difference in equilibrium concentrations of CO2(g) between the two cases (as Na doesn't show up anywhere in the system you posted). $\endgroup$
    – Hadi Khan
    Commented Feb 5 at 21:20
  • 1
    $\begingroup$ Conditions are very different. pH is the key. $\endgroup$
    – Poutnik
    Commented Feb 5 at 21:27
  • 1
    $\begingroup$ Research the use of baking soda in baking, specifically soda bread; you will find at high temperatures bicarbonate does fizz. Aso the 400+ ppm of CO2 in the air raises the CO2 level in the water inhibiting the hydrolysis of HCO3- to give H2CO3 or CO2. Purging a bicarbonate solution with CO2 free air should eventually decompose all the bicarbonate. $\endgroup$
    – jimchmst
    Commented Feb 5 at 22:57
  • $\begingroup$ It certainly effervesces in hot enough water $\endgroup$
    – მამუკა ჯიბლაძე
    Commented Feb 6 at 17:24