# Abreathing mixture used by deep sea divers contains helium, oxygen, and carbon dioxide. What is the partial pressure of oxygen at 1 atmosphere if P He- 609.5 mm Hg and P CO_2 = 0.5 mm Hg?

Jan 12, 2017

The sum of the partial pressure are $1 \cdot a t m$

${p}_{{O}_{2}} \cong 0.20 \cdot a t m$

#### Explanation:

$\Sigma {p}_{i} = 1 \cdot a t m$, where ${p}_{i}$ are the individual partial pressures.

And thus ${p}_{C {O}_{2}} + {p}_{{O}_{2}} + {p}_{H e} = 760 \cdot m m \cdot H g$

And thus, ${p}_{{O}_{2}} = \left\{760 - {p}_{C {O}_{2}} - {p}_{H e}\right\} \cdot m m \cdot H g$

${p}_{{O}_{2}} = \left\{760 - 0.5 - 609.5\right\} \cdot m m \cdot H g$

${p}_{{O}_{2}} = 150 \cdot m m \cdot H g$

And we convert ${p}_{{O}_{2}}$ to atmospheres, knowing that $1 \cdot a t m \equiv 760 \cdot m m \cdot H g$.

p_(O_2)=(150*mm*Hg)/(760*mm*Hg*atm^-1)=??atm