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?

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Answer 1 · 2016-05-26T22:56:46

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

Use the Ieal Gas Law to get this answer.

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

A nebula's a region of the galaxy where new stars are forming contains a very tenuous gas with 128 a t o m sa t o m s/cm^3/cm^3. This gas is heated to 7459 K7459 K by ultraviolet radiation from nearby stars. What is the gas pressure?