Posted by Anna on .
A solution of hydrogen peroxide, H2O2, is titrated with a solution of potassium permanganate, KMnO4.
It requires 51.7 mL of 0.145 M KMnO4 to titrate 20.0 g of the solution of hydrogen peroxide. What is the mass percentage of H2O2 in the solution?
If you want the whole equation I'll type it but it's long. I think all you need is the mole ratio which is 5 mol H202 : 2 mol KMnO4.
so far I changed 51.7 mL to L. Got .00750 mol KMnO4 using molarity and volume. converted that to .0188 mol H2O2.
AP Chem -
You may have almost finished it then but I'll start from the beginning.
Convert M x L KMnO4 to mols.
Convert mols KMnO4 to mols H2O2 using the coefficients in the balanced equation.
Convert mols H2O2 to grams H2O2.
Then %H2O2 = [grams H2O2/mass of sample]*100.
Mass of the sample is 20.0 g in the problem.