# A 1.2-liter tank at a temperature of 27°C contains a mixture of 1.5 moles of oxygen, 1.2 moles of nitrogen, and 1.6 moles of hydrogen. What is the total pressure of the mixture inside the tank?

Jun 5, 2016

Approx. $88 \cdot a t m$

#### Explanation:

Dalton's law of partial pressures states that in a gaseous mixture, the pressure exerted by a component is the same as it would exert if it alone occupied the container. The total pressure os the sum of the individual partial pressures.

So, there are $4.3$ moles of gas occupying the container, and we assume Ideal Gas behaviour:

$P = \frac{n R T}{V}$ $=$ $\frac{4.3 \cdot m o l \times 0.0821 \cdot L \cdot a t m \cdot {K}^{-} 1 \cdot m o {l}^{-} 1 \times 300 \cdot K}{1.2 \cdot L}$

This is quite a high pressure; of course, as you know $1$ $m o l$ of gas would occupy approx $25 \cdot L$ under standard conditions of $1$ $a t m$ and $298 K$.