# Five gases combined in a gas cylinder have the following partial pressures 3.00 atm (N_2), 1.80 atm (O_2), 0.29 atm (Ar), 0.18 atm (He), and 0.10 atm (H). What is the total pressure that is exerted by the gases?

##### 1 Answer
Jun 10, 2017

${P}_{\text{Total}} \cong 5.4 \cdot a t m$

#### Explanation:

Old $\text{Dalton's Law of Partial Pressures}$ states that in a gaseous mixture, the partial pressure exerted by a component gas is the same as it would have exerted if it alone occupied the container. The total pressure is the sum of the individual partial pressures.

For your problem, we have 5 component gases that are not expected to react with each other........

${P}_{\text{Total}} = {P}_{{N}_{2}} + {P}_{{O}_{2}} + {P}_{A r} + {P}_{H e} + {P}_{{H}_{2}}$ (NB as written the problem says atomic hydrogen, which I don't think you got!).

And so............

${P}_{\text{Total}} = \left\{3.00 + 1.80 + 0.29 + 0.18 + 0.10\right\} \cdot a t m$

Note also that given the gas laws, the partial pressures may be used to find the mole fraction of each component:

$\text{Mole fraction,}$ "N_2=(3.00*atm)/({3.00+1.80+0.29+0.18+0.10}*atm)#

$= 0.55$ etc.