Ksp vs Keq equation set up

[super112]

This may be a dumb question, but in regards to this equation, am I setting up the two equations correctly (in regards to adding exponents b/c of molar ratio)?

Ag2SO4(s) --> 2Ag+ (aq) + SO4 2- (aq)

Ksp = (2x)^2 • (x)

Keq= [Ag+] • [SO4 2-]
. . . . . . . [Ag2SO4]

Thanks

---

Members don't see this ad.

 

[FeralisExtremum]

Ag2SO4, being a solid, shouldn't show up in your Keq (solids and liquids have an activity of '1', so they contribute nothing to the expression). The [Ag+] should be [Ag+]^2. The set up you have to solve the Ksp expression looks correct.

Also keep in mind, Keq and Ksp aren't different things - Ksp is just a specific form of a Keq expression we use for solids dissolving in aqueous solutions. They are set up exactly the same. The stuff we do with the X's in Ksp questions isn't actually part of the expression - it's something we plug in to the expression to solve for how much dissolves.

 

[super112]

oops, I guess I messed up my example with the solid, haha thanks for catching that. But as long as the exponents are correct then I'm happy. I've been having problems remembering that. And thanks for monitoring the forums so well, you answered a few of my questions really well!