Determining the Mass percent comp. of an Aqueous Hydrogen peroxide

[Marie123]

Homework Statement

In lab we recorded a barometric pressure of 768.2 torr. Suppose we didn't have access to a barometer and assumed that atmospheric pressure was 760 mm Hg. Would the mass percent of hydrogen peroxide that you calculated for the solution be higher or lower than the value you obtained using the actual barometric pressure.

Homework Equations

The Attempt at a Solution

I think it would be lower (I did it through calculations) but was wondering why it would be the lower or simply the science behind why it would be lower. Thanks!

 

[Bohrok]

Do you have a formula that you used for calculating the hydrogen peroxide from the barometric pressure?

 

[Marie123]

i just used pv=nrt
2H2O2 (aq) -> 2H2O (l) + O2 (g)