H2O + SO2 --> H2SO3

[704320688]

Question 1: I know that the SO2 is the lewis acid and the H2O is the lewis base; however, is SO2 also a bronsted acid?? Does it make a difference if it is aqueous or not because if it is aqueous, it will dissociate further into SO3^2- + 2 H3O+

Also, I have a separate question if you don't mind:

Question 2: When do products dissociate more? Do they only dissociate more if the products are strong acids/bases (i.e. sometimes conjugates of weak acids/bases) or if the products are aqueous salts?

[704320688]

What I mean by that is that weak acids and bases dissociate so negligibly that we wouldn't split them up in the end reaction.

[powerberry]

Question 1: I know that the SO2 is the lewis acid and the H2O is the lewis base; however, is SO2 also a bronsted acid?? Does it make a difference if it is aqueous or not because if it is aqueous, it will dissociate further into SO3^2- + 2 H3O+

To dissociate means it is aqueous.

In 2H2O + H2SO3 --> 2H3O(+) + SO3(2-)
H2SO3 acts as the Bronsted acid, and its conjugate base is SO3(2-).
H2O acts as the base with H3O+ as its conjugate acid.

But in the reverse reaction
2H3O(+) + SO3(2-) --> 2H2O + H2SO3
SO3 accepts protons, so it would act as Bronsted base.

[Chem_Mod]

Question 2: When do products dissociate more? Do they only dissociate more if the products are strong acids/bases (i.e. sometimes conjugates of weak acids/bases) or if the products are aqueous salts?

Both strong acids/bases (e.g. HCl, NaOH) and salts (NaCl, NaCN) will dissociate completely. Weak acids and bases are defined as molecules that do not completely dissociate.

[powerberry]

Question 2: When do products dissociate more? Do they only dissociate more if the products are strong acids/bases (i.e. sometimes conjugates of weak acids/bases) or if the products are aqueous salts?

When you have a reaction that produces a strong acid/base, those will definitely dissociate. Otherwise, you would still write them as aqueous but since not all of it dissociates you would write them together (e.g. CH3COOH) and then write an reversible reaction on the next part to show that some of it may dissociate.

http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.htmlHere are a bunch of rules about which salts will actually dissociate in solution!

[Chem_Mod]

http://www.files.chem.vt.edu/RVGS/ACT/notes/solubility_rules.htmlHere are a bunch of rules about which salts will actually dissociate in solution!

We will not be discussing solubility equilibria for salts in this class. Any salts that we give you will completely dissociate. Please don't overthink it.

[704320688]

Hi Poweryberry,
First of all, thank you so much for the quickly reply! I am, however, a bit confused by the SO3 stuff because my question is about SO2 and H2O. Specifically, my question is about the rxn H2O + SO2 --> H2SO3 and whether or not it fits within the bronsted definition of a acid and bases.

[Chem_Mod]

H₂O + SO₂ <==> H⁺ + HSO₃^-

or if you want to think of in terms of hydronium ions

2H₂O + SO₂ <==> H₃O⁺ + HSO₃^-

From the above, since the proton from the water is donated, it will fit the Bronsted-Lowry Acid-Base theory.

[704320688]

When would we dissociate the H2SO3 further and when would we just keep it as H2SO3?

[powerberry]

Chem_Mod, thanks for letting me know!

[704320688]

Thank you both for your help!