a 500ml sample of oxygen gas at 24 degree celsius was prepared by decomposing a 3% aqueous soution of hydrogen peroxide in the presence of manganese catalyst by the reaction: 2h2o2 = 2 h20 + o2...

the oxygen was colletec by displacement of water. the total pressure of gas collected was 755 mmHG. THe vapoer of water at 24 dgree celsius is 23 mmHG.
A. What is the partial pressure of oxygen gas in the mixture?
b. How many moles of oxygen gas are in the mixture?

Please help? I'm not sure where to start!

1 answer

PO2 = Ptotal - PH2O vapor.

Use PV = nRT to solve for n = moles O2 gas.
For P use the partial pressure of O2 from the a part. Don't forget to convert T to kelvin.