Question #a5ed9

1 Answer
Dec 22, 2017

#"4.9 atm"#.


The idea here is that the partial pressure of carbon dioxide will depend on its mole fraction as described by Dalton's Law of Partial Pressures.

More specifically, the partial pressure of carbon dioxide, #P_ ("CO"_ 2)#, will be directly proportional to the mole fraction of the gas, #chi_ ("CO"_ 2)#.

#color(blue)(ul(color(black)(P_ ("CO"_ 2) = chi_ ("CO"_ 2) * P_"total")))#

Here #P_"total"# represents the total pressure of the mixture.

The mole fraction of a gas that's part of a gaseous mixture can be calculated by dividing the number of moles of carbon dioxide by the total number of moles present in the mixture.

#chi_ ("CO"_ 2) = (3.5 color(red)(cancel(color(black)("moles"))))/((1.5 + 3.5)color(red)(cancel(color(black)("moles")))) = 7/10#

This means that the partial pressure of carbon dioxide will be equal to

#color(darkgreen)(ul(color(black)(P_ ("CO"_ 2)))) = 7/10 * "7.0 atm" = color(darkgreen)(ul(color(black)("4.9 atm")))#

The answer is rounded to two sig figs.