Question

What is the density of neon gas given a pressure of `505*mm*Hg`, and a temperature of `318*K`?

What is the density of neon gas given a pressure of `505*mm*Hg`, and a temperature of `318*K`?

Answer 1

We assume a litre volume of gas under these conditions.

And get `rho=0.5*g*L^-1`

Explanation:

Now, we know `PV=nRT`, for an Ideal Gas, and we ASSUME that neon will approximate Ideal Gas behaviour.

From the equation: `P/(RT)=n/V=("mass"/"molar mass")/V`

`P/(RT)=("mass"/"molar mass")/V=rhoxx1/"molar mass"`

And thus, (FINALLY!): `rho=P/(RT)xx"molar mass"`

And we plug in the given numbers:

`rho=((505*mm*Hg)/(760*mm*Hg*atm^-1)xx20.18*g*mol^-1)/(0.0821*(L*atm)/(K^-1*mol^-1)xx318*K)~=0.51*g*L^-1`

The units are appropriate for density, as we require. Please check my figures and assumptions; there is a lot of 'rithmetic here.