[Melon]

Hello everyone, recently under the Chapter of Alkenes, I've learnt that upon strong oxidation of C=C bond with hot,acidic KMnO4, the terminal carbon bonded by a C=C bond will be oxidised into carbonic acid, and the final oxidised product will be CO2 and H2O.

Though I understand that H2CO3 can dissociate, I was just wondering how is it possible for a slightly soluble product like H2CO3(aq) to form a gaseous CO2?

Thank you very much!

[Babcock_Hall]

Did you try writing a balanced equation?

[Melon]

Did you try writing a balanced equation?

When I researched, I found out that carbonic acid dissociates to give H+ ions and HCO3- ions.
I consulted my tutor regarding this problem today, and she just mentioned that because of the heating, some of the carbonic acid would just be unable to remain in the solution and become carbon dioxide, but I'm still abit unconvinced by this explanation...

[Borek]

Dissolution of CO₂ is an equilibrium process, every solution of H₂CO₃ is in an equilibrium with gaseous CO₂, this is GenChem101.

[Arkcon]

There's a lot here, but its all over the place.  Let's try to work through it all.

First off, you've posted in High School Chemistry, but some concepts are more advanced, but you seem to missing some basics.  Which is fine, we're glad to help anyone, but having to reteach you the basics, while covering the advanced, is more work for us.

Re: Strong Oxidation of Carbon-Carbon Double Bond

This title has almost no bearing at all one the question setup or content.  So.  Again.  Not a problem, really.  But still, extra work.

Hello everyone, recently under the Chapter of Alkenes, I've learnt that upon strong oxidation of C=C bond with hot,acidic KMnO4, the terminal carbon bonded by a C=C bond will be oxidised into carbonic acid, and the final oxidised product will be CO2 and H2O.

OK.  That's a good reaction to learn.  There's also this one:

Na₂CO₃ + 2 H⁺  2 Na⁺ + H₂CO₃  CO₂ + H₂O +2 Na⁺

So we could have just worked with that reaction, given the next questions you ask.

Though I understand that H2CO3 can dissociate,

Yes it can:  https://en.wikipedia.org/wiki/Carbonic_acid#Acidity_of_carbonic_acid

That reference introduces a number of concepts you're ignoring.  The pKa is low, and is also affected by pressure and temperature.  Also, dissociation of carbonic acid give H+, not the CO₂ plus water.  Just letting you know we're getting muddled with the definitions here.

I was just wondering how is it possible for a slightly soluble product like H2CO3(aq) to form a gaseous CO2?

This is a decomposition reaction.  Some things decompose.  Some things, called acids, dissociate into H+.  And some ionic salts dissociate into ions, in water.  And some do more than one, at once, or so rapidly we only see one.  You can ask again, if this bit is still confusing, but I don't know how to say that clearer.

[Chetan Bhandari]

Its correct that C=C on strong oxidation gives out CO2 through a intermediate as carbonic acid.
This is how its formed:
C=C when subjected to strong oxidizing agents in presence of water-
           C=C + H20 H2C03
Since it is sparingly soluble in water, it will be in equilibrium as
          H2C03  H2O(l) + CO2(g)
When enough heat is achieved, CO2 escapes as gas to atmosphere.

[Vidya]

Though I understand that H2CO3 can dissociate, I was just wondering how is it possible for a slightly soluble product like H2CO3(aq) to form a gaseous CO2?

Thank you very much!

Do you know that when CO2 gas is dissolved in water ,carbonic acid is formed?
  H2O(l) + CO2(g)    H2CO3