# Question #57b80

May 9, 2017

$\frac{P V}{T} = \frac{P V}{T}$ : Combined Gas Law

Not sure if the psi value you were given is psia or psig. If it's psig, make sure you add 14.7 to make it absolute!

I add 273.15 to the temperature to convert it from celsius to kelvin (Kelvin is absolute. You need to use absolute values when working with gases, unfortunately)

$\frac{40 \cdot 0.85}{273.15} = \frac{x \cdot 0.85}{308.15}$

$\frac{34}{273.15} = \frac{x \cdot 0.85}{308.15}$

$0.124474 = \frac{0.85 x}{308.15}$

$38.35658 = 0.85 x$

$x = 45.12538898$

You can plug $x$ back in to check. If your equation works out (both sides are equal), you did it right! (Which I did, and it works)

Hope this helps!