[Arthr2shedsJacksn]

Hi! Please try and see if you can help me solve this!

I am given the volume of distilled water, no temperature figure, no pressure values.
It is a reaction between hydrogen peroxide and a catalyst, both of which are given their volumes and concentrations. Oxygen is produced over a period of time. Somehow, partial pressure works into this calculation.
I have absolutely no idea what to do. I don't even know what the reaction equation looks like!

Do I need any external values, or can I solve it on its own?

[Borek]

Not sure if I understand - you have known volume of distilled water, so where does hydrogen peroxide comes to the scene? What do you have to find?

Water vapour pressure is a thing you have to take from tables and it is temperature dependent. However, for some calculations you may be interested not in the gas volume itself, but in its change. Then you may be able to ignore water partial pressure.