Homework help

[Randomgal]

I have 2 questions on my homework that I have been stuck on for the past few days so I was wondering if anyone here could help. The questions are:
50 ml of a .1 M sodium oxalate solution is titrated with a .2 M potassium permanganate solution to it's endpoint in acid solution. The redox products are manganese +2 ion and caebon dioxide gas. Determine the volume of potassium permanganate required to complete the titration.
AND:
A 300 ml water sample was taken from a stream in Mexico City and analyzed for dissolved oxygen. Using the winkler method, 58.88 ml of 2.42 x 10^-3 M solution thiosulfate titrant was required. Calculate the dissolved oxygen in the water and express this as mg/L.

Any help on either problem would be amazing! Thanks!

[ChenBeier]

For the first one develop the chemical equation, C₂O₄ 2- and MnO₄- are the start point
If you have the equation read how many mole oxalate refers to how many mole permanganate. With this ratio you can calculate with the given samples.

Read the Winkler method

https://chemistry.stackexchange.com/que ... r-s-method