5I.5

[Ilan Yafeh 1K]

Hi everyone!
This question is confusing me just because it deals with bar and asks for the partial pressure?
In a gas-phase equilibrium mixture of PCl5, PCl3, and Cl2 at 500. K, PpCl5=1.18 bar, Pcl2=5.43 bar. What is the partial pressure of PCl3, given that K=25 for the reaction PCl5(g)<> PCl3(g) +Cl2(g) ?

[Anahi C 2F]

Due to all the partial pressures being in bar, no conversion has to be done. Instead we go ahead and do a regular equilibrium constant problem. In this case, , which gives us . Plugging in the values given, , we get the value of 5.4. Therefore, bar.

[joselle barnoya 1k]

Just to further solidify this, you can talk about pressure with atm or bar or Torr. All that matters for calculating k is that for all the values in the equation, their units are the same. Since we are dividing bar / bar or atm/atm the units will cancel anyways so as long as all your values have the same units it's fine.