A sample of KHC2O4 weighing 0.5839 g is dissolved in 25 mL of water and an endpoint is reached when 31.99 mL of KOH has been added. Calculate the molarity of the KOH solution.

KHC2O4(aq) + KOH(aq) �¨ K2C2O4(aq) + H2O(l)

because the coefficents are all the same, i just assumed that KOH also had 0.5839 g, converted into mols, and divdied by the total volume. however, this answer was wrong...

1 answer

I'm not surprised the answer was wrong.
Chemical reactions are by mols and not by grams; therefore, 1 mol of each reactant produces 1 mol of each product but a mol is not a gram.
SO, convert 0.5839 g KHC2O4 to mols, convert mols KHC2O4 to mols KOH (that's the 1:1 part), then calculate the molarity of KOH. Post your work if you get stuck. I expect you will have no trouble.