Question

A nebula's a region of the galaxy where new stars are forming contains a very tenuous gas with 128 `a t o m s``/cm^3`. This gas is heated to `7459 K` by ultraviolet radiation from nearby stars. What is the gas pressure?

Answer 1

Pressure = `1.318\times10^{-11}" Pa"`.

Use the Ieal Gas Law to get this answer.

Explanation:

For this purpose we render the Ideal Gas Law on an atomic basis instead of the usual molar basis:

(Pressure)`\times`(Volume)
= (Boltzmann's constant)`\times`(No. of atoms)`\times`(Absolute temprerature)

Volume = `1\times10^{-6}" m"^3`

Boltzmann's constant = `1.3806\times10^{-23}" J/K"`

No. of atoms = `128`

Absolute temperature = `7459" K"`

So

(Pressure)#\times(1\times10^{-6}" m"^3) = (1.3806\times10^{-23}" J/K")\times(128)\times(7459" K")#

Pressure = `1.318\times10^{-11}" J/m"^3=1.318\times10^{-11}" Pa"`