[imrahil_SVK]

2NaOH + K2SO4 2KOH + Na2SO4

pls help 

[Arkcon]

Not a specific enough question.  Aqueous?  Then no, all reactants and products are soluble.  Unless you intend multiple fractional crystallizations, but, why?

[billnotgatez]

i think this was a general chem or high school chem question

[Arkcon]

i think this was a general chem or high school chem question

Really, that's a possibility of course, anything is.  But it seems like a pretty dumb question for a text book or a teacher to ask, it does kinda lead nowhere, doesn't it.  When I took high school chemistry, i asked a similar questions, I carefully picked soluble reactants and products, and asked the teacher what would happen.  She looked at the periodic table for a minute, and said the reaction wouldn't occur.  I'm guessing I had the electronegativities wrong for the reaction to work.  But still, this question reminded me of mine, from way back when.

[hmx9123]

It's all a matter of relative solubility:

Potassium sulfate: 12g/100mL water at RT, 24.1g/100mL at 100°C
Potassium hydroxide: 107 (at 15°C), 178 @ 100°C
Sodium sulfate: 11 @ 0°, 92.7 @ 30° (probably way higher at boiling)
Sodium hydroxide: 42 @ 0°, 347 @ 100°

So, looking at that, you're going to have a hard time getting the reaction to go.  Since potassium sulfate is the least soluble component, you're going to be hard pressed to force equilibrium to the right.  At room temp, it's the least soluble component, and at higher temps, it's still the least soluble component.

Don't know why anyone would want to make KOH this way since you can just buy it at the store anyway.

[DrCMS]

Sodium sulfate: 11 @ 0°, 92.7 @ 30° (probably way higher at boiling)

Go look at the solubility against temperature curve and be surprised.

http://en.wikipedia.org/wiki/Sodium_sulfate

note the maximum solubility of Na₂SO₄ is 49.7g/100ml @32.4°C, 4.7g/100ml @0°C and 42.7g/100ml @100°C

[hmx9123]

Now that is weird.  I looked in the CRC and found the two data points, assuming a straight line.  Holy crap, that solubility is weird.  In any case, you'd be hard pressed to get KOH out of solution.  I'm not sure which is more correct, the Wikipedia entry of 4.7g/100mL water at 0°C, or the CRC's value of 11g.  If Wikipedia is correct, you may VERY slowly be able to remove sodium sulfate from solution as a precipitate, thereby pushing equilibrium to the right, but it is doubtful.

[UnintentionalChaos]

If you have K2SO4 and want to convert to KOH, I suggest you boil with a stoichiometric amount of calcium hydroxide and filter out the gypsum crystals which might take a while to finish forming...it likes to make supersaturated solutions and then slowly crystallizes out over a few days. Like it was suggested though, you can buy it at the store.