I'm gonna be doing a project that calls for "10ml of a 10% solution of KOH in 95% ethanol"
So here's my question. What's the right way to figure out how much KOH to put in the 10ml of ethanol?
If the ethanol is 7.89g, do I just take 10% of that (.79g)?
Or do I go by moles?
I did the math in moles and got about .94g of KOH.
So what way is right? Or with such a small difference does it even matter?
[Edited on 31-1-2014 by arkallic]DraconicAcid - 30-1-2014 at 16:11
The 10% is almost certainly by mass (although some chemists would use mass/volume percent, which is easy, yet ridiculous), never moles. That would
give you 0.8 g of KOH, or 1 g KOH if it's mass/vol%. In most applications, it probably won't matter, because your potassium hydroxide isn't pure
anyway (commercial KOH is probably 96-98% KOH, with the rest being potassium carbonate and water)arkallic - 30-1-2014 at 16:15
