What is partial pressure of oxygen at sea level?

1 Answer
Sep 4, 2017

Answer:

#P_(O_2)=0.21xx1*atm#

Explanation:

This illustrates old Dalton's Law of Partial Pressures. In a gaseous mixture, the partial pressure exerted by a component gas is the same as if it alone occupied the container.....

#P_"Total"=SigmaP_"component gases"#

#=P_1+P_2.....+P_n#, assuming ideality.....

#P_"Total"=(n_1RT)/V+............(n_nRT)/V#

#P_"Total"=(RT)/V{n_1+n_2+....n_n}#

And thus #P_1/P_"Total"=((RT)/Vn_1)/((RT)/V{n_1+n_2+....n_n})#

#P_1/P_"Total"=(n_1)/({n_1+n_2+....n_n})=chi_(n_1)#

Where #chi_(n_1)="mole fraction of the component "#

And here the container is conveniently the atmosphere, which to a first approx. is #78%# dinitrogen, and #21%# dioxygen......

And so what is #P_(O_2)#?