A gaseous mixture at 780mmHg pressure contains carbon dioxide, and dioxygen. If PCO2=560mmHg, what is PO2?

1 Answer
Apr 17, 2017

Well it is nominally 220mmHg.

Explanation:

PTotal=PCO2+PO2

PO2=PTotalPCO2=(780560)mmHg.

Dalton's Law of partial pressures states that in a gaseous mixture, the partial pressure exerted by a component is the same as the pressure if it alone occupied the container. The total pressure is the sum of the individual partial pressures.

And thus for atmospheric pressure, we can state that.........

Ptotal=PN2+PO2+Pother gases=1atm.

In practice, you DO NOT use a mercury column to measure a pressure OVER 1atm. Try to do this and you will likely get mercury all over the lab.