For sulfurous acid, the Ka1=?

Question

nottim · Answer

Doing review here, and...I don't think I remember the unit

nottim · Answer

$$K _{a _{1}}$$

nottim · Answer

For sulfurous acid, the concrentration something is...

nottim · Answer

I don't think math is involved...is it?

nottim · Answer

This is a multiple choice thing...

nottim · Answer

[SO32-][H1+]2 / [H2SO3]	d.	[HSO31-][H1+] / [H2SO3]
[HSO42-][H1+] / [H2SO3]	e.	[H2SO3] / [SO31-][H1+]2
[SO31-][H1+]2 / [H2SO3]

nottim · Answer

attachment

nottim · Answer

there's the question. here's the review pakage file

abb0t · Answer

Well, if I remember correctly, it's a two step process for the dissociation of sulfurous acid...
you can rule out option B because sulfurous acid has 3 oxygens, not 4. 
You can also rule out option A and C because those would be Ka2 after dissociation. And you're left with E and D.

And to find K, it's products over reactants, so my guess is that it's option D.

nottim · Answer

Why was SO3^2- a reactant (in the other answers)?

abb0t · Answer

Like I said before, it's a two step process. Seeing as how sulfurous acid is a pretty strong acid, it will completely dissociate both hydrogens. 2 moles of H+ per mole of acid.