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What is the molarity of 50% KOH?
I know 45% KOH is 11.5M. THanks in advance!
The solution is 50% by weight. I have read that the molarity of 45% KOH is 11.5-11.7M. Is this not correct?
2 Answers
- Anonymous1 decade agoFavorite Answer
12.72M
- GTBLv 71 decade ago
Let's assume 50% KOH is 50 % weight / volume in water.
This means in 1 liter of water, there is 500 grams of KOH dissolved.
KOH moleculear weight is 40 + 16 + 1 = 57 grams / mole
500 grams KOH / (57 grams KOH / mole KOH) = (500/57) moles KOH in one liter.
Therefore the molarity of 50% KOH is (500/57) = 8.77 M.
This casts doubt on your statement that 45% KOH is 11.5 Molar.
Now for the unknown - which is "What is meant by 50%? Is it weigh / volume, is weight / weight (in which case we need to know the density of the 50% solution), etc.
This is why the % concentration must be defined a lot better to be useful.