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?

1 Answer
May 26, 2016

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"#