# Problem: Assume that an exhaled breath of air consists of 74.7 % N2, 15.4 % O2, 3.8 % CO2, and 6.1 % water vapor.If the total pressure of the gases is 0.990 atm , calculate the partial pressure of water vapor.

###### FREE Expert Solution

We’re being asked to calculate the partial pressure of water vapor in a gas mixture composed of 74.7 % N215.4 % O23.8 % CO2, and 6.1 % water vapor with a total pressure of 0.990 atm.

Recall that the partial pressure of a gas (PGas) in a mixture is given by:

$\overline{){{\mathbf{P}}}_{{\mathbf{gas}}}{\mathbf{=}}{{\mathbf{\chi }}}_{{\mathbf{gas}}}{{\mathbf{P}}}_{{\mathbf{total}}}}$

where:

χGas = mole fraction of the gas

Ptotal = total pressure of the gas mixture

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###### Problem Details

Assume that an exhaled breath of air consists of 74.7 % N2, 15.4 % O2, 3.8 % CO2, and 6.1 % water vapor.

If the total pressure of the gases is 0.990 atm , calculate the partial pressure of water vapor.