a 500ml sample of o2 gas at 24 degrees celsius was prepared by decomposing a 3% aqueous solution of hydrogen peroxide, in this presence of a small amount of manganese catalyst by the reaction 2H2O2>2H2O+O2. The oxygen thus prepared was collected by displacement of water. The total pressure of gas collected was 755mm Hg. What is the partial pressure of O2 in the mixture? How many moles of O2 are in the mixture? (The vapor pressure of water at 24 degrees C is 23mm Hg.)

Answer 1

Ptotal = pO2 + pH2O
You know Ptotal and pH2O; solve for pO2.

Find moles from PV = nRT.