In a volumetric analysis experiment, a solution of sodium oxalate (Na₂C₂O₄) in acidic solution in titrated with a solution of potassium permanganate (KMnO₄) according to the following balanced chemical equation

It required 40.0 mL of 0.0335 M KMnO₄ to reach the endpoint. What mass of Na₂C₂O₄ was present initially?
A. 0.179 g
B. 1.79 g
C. 0.0718 g
D. 11.2 g
E. 0.448 g

0.448 g

Explanation:

The first step is to obtain the number of moles of KMnO4 reacted from the data given at end point. We now apply this result together with data from the balanced reaction equation in a simple proportion to obtain the amount of sodium oxalate that reacted. We then calculate the molar mass of the sodium oxalate and multiply this molar mass by number of moles of oxalate reacted in order to obtain the mass of oxalate reacted. See image attached for details.

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )