What is the relationship between temperature and volume in a redox titration?

Question

I am currently doing an experiment to answer how changing storage temperature of a H2O2 solution affect its concentration, by titration against KMnO4. My results show that when temperature increases, the titre volume (final volume - inital volume) decreases and concentration decreases. Volume is temperature dependent, so why does the titre volume decrease when temperature increases? 

Answer 1

If I understand your question, you are storing the H2O2 under different conditions of temperature, and testing how that affect the concentration of H2O2 and the volume of H2O2. Is that correct? If so, you are essentially looking at the decomposition of H2O2 as follows:

2H₂O₂ ==> 2H₂O + O₂(g)

I'd be surprised if you saw any change in volume unless there is evaporation. You would see a decrease in concentration because the H₂O₂ is turning into H₂O. So, if you have evaporation at higher temperatures, and you also are losing H₂O₂ by decomposition, depending at the magnitude of each effect, you could get an increase, decrease, or no change in the concentration of the H₂O₂.