2 KMnO4 + 5 H2C2O4 + 3 H2SO4 ---> 2 MnSO4 + 10 CO2 + 8 H2O + K2SO4

How many milliliters of a 0.123 M KMnO4 solution is needed to react completely with 3.141 of oxalic acid?

Please help I've worked this every way I know.

Ok so you take 3.141g and divide that by 90.036?

Yes, for step 2.

Thanks. The problem I was having, I would multiply the grams by the molar mass by everything else I done was correct to what you were saying. What I don't understand is why you divide and not multiple(I do this for when it says a volume of somthing and get the right answer)

I don't understand much of what you have written. For the mols oxalic acid, it is grams = mols x molar mass. If you know molar mass and grams and you want mols, that is

g = mols x molar mass
g/molar mass = mols x molar mass/molar mass

Now on the right side, molar mass in the numerator cancels with the molar mass in the denominator to leave just mols and that makes mols = grams/molar mass.
If you give an example of what you are talking about with the volume, perhaps I can help with that too. I think your problem is one of algebra.
If g = mols x molar mass, then
g/molar mass must = mols.

It's 0.854 M NaOH solution react completely with 2.1 L of a 0.972 M BaCl2. It's a 2:1 but I see what I did. Late nights sometimes mess with ya.

Thank you. Might need help In the future.

glad to help

This four step process will just about work them all. Print this and save it.

1. Write and balance the equation. You've done that.

2. mols H2C2O4 = grams/molar mass = ?

3. Using the coefficients in the balanced equation, convert mols H2C2O4 5o mols KMnO4. That will be mols H2C2O4 x 2/5 = ?

4. M KMnO4 = mols KMnO4/L KMnO4
You know mols and M, solve for L and convert to mL.

Post your work if you get stuck but remember this 4-step process.

4.