This question is from grade 12 university preparation level. The answer has to do something with rates of chemical reactions but I don't know what the answer is.

. When hydrogen peroxide H2O2 is used as an antiseptic on open wounds, bubbles form as a result of the following chemical reaction.

H2O2(aq) --------------> 2H2O(l) + O2(g)

This same hydrogen peroxide decomposes very slowly via the same chemical reaction when left in a bottle, even if temperature is increased to 36.8 oC (body temperature). Explain the two observations.

4 answers

Blood contains a protein and that acts as a catalyst t speed up the rate of the decomositioin. H2O2 in a bottle aty body temperature contains no catalyst.
I know increasing the temperature doesn't increase the rate of reaction of all reactions but why doesn't the rate of reaction increase in this situation?
The point is that the H2O2 lasts for a long time if kept on a shelf in its original bottle (which by the way is dark to keep photons from encouraging decomposition). The effect of temperature is minor if in the range from room temp to body temp.
However if you pour it on your bleeding wrist, your blood encourages the decomposition as a little waming never would.
Damon is right. You've missed the whole point. The point is that H2O2 in a dark bottle (capped) in a dark room at 3 o C will decompose but very very slowly over time. H2O2 at 37o C poured on a cut (with blood) decomposes much more rapidly because the blood acts as a catalyst. Look up in your text or in a dictionary and read about a catalyst and how a catalyst affect the rate of a reaction.