## Trending News

# What is the final pressure of helium and neon gas mixture in this case?

I wrongly selected incorrect answer as favourite answer. Another answer final pressure p=6.67 bar is the correct and favourite answer with 5 stars.

### 2 Answers

- Roger the MoleLv 72 months agoFavorite Answer
((10.0 mol x 5.00 bar) + (5.00 mol x 20.0 bar)) / (10.0 mol + 5.00 mol) = 10.0 bar

- 2 months ago
We can treat noble gasses as ideal gasses, which means we can use the formula pV=nRT, which is independent of the actual type of gas.

Let the first container have n₁ moles, pressure p₁, and volume V₁.

Let the second container have n₂, p₂, and V₂.

Let the temperature be T, and let the final pressure be p.

Then we have:

p₁V₁=n₁RT

p₂V₂=n₂RT,

p(V₁+V₂)=(n₁+n₂)RT

Since we do not know the volumes, we will eliminate them from the equations:

V₁=n₁RT/p1

V₂=n₂RT/p2

p(V₁+V₂)=(n₁+n₂)RT

⟹p=(n₁+n₂)RT/(V₁+V₂)=(n₁+n₂)RT/(n₁RT/p₁+n₂RT/p₂)

=n₁+n₂/(n₁/p₁+n₂p₂)

=10.0+5.00/(10.0/5.00+5.00/20.0)=6.67bar

The final pressure should be p=6.67bar.