# A tank contains helium gas at 490 mm Hg, nitrogen gas at 0.75 atm, and neon at 520 torr. What is the total pressure in atm?

Jul 16, 2016

Approx. 2 atmospheres.

#### Explanation:

The total pressure is the sum of the individual partial pressures of each gas. The gases were quoted with unrealistically different units.

$1$ $\text{atmosphere = 760 mm Hg = 760 Torr}$. You must convert the partial pressures to common units, and simply add them up.

And so......

${P}_{\text{Total}} = {P}_{H e} + {P}_{{N}_{2}} + {P}_{N e}$, and we can convert all the units to atmospheres......

P_"He"=(490*"Torr")/(760*"Torr"*atm^-1)=0.645*atm.

${P}_{{N}_{2}} = 0.75 \cdot a t m$.

P_"Ne"=(520*"Torr")/(760*"Torr"*atm^-1)=0.684*atm.

${P}_{\text{Total}} = \left\{0.645 + 0.75 + 0.684\right\} \cdot a t m = 2.08 \cdot a t m$.