Equilibrium partial pressures

[juchung7]

For question 63 in chapter 11
At 25 C, K =3.2 x 10^-34 for the reaction 2 HCl(g) <-> H2(g) + Cl2(g). If a 1.0-L reaction vessel is filled with HCl at 0.22 bar, what are the equilibrium partial pressures of HCl, H2, and Cl2?

Do you have to solve this by first calculating number of moles of HCl using PV=nRT and then later converting moles of H2 and Cl2 back to pressure? Or can you just use pressure and K to solve for the partial pressures?

[Sabah Islam 1G]

Since the question is asking for the equilibrium partial pressures, it would not be necessary to calculate the number of moles using PV=nRT. You would just have to use the pressure of HCl that is already given, do the ICE table, and use K, which would compute the partial pressures.

[Guadalupe T 1E]

Dr Lavelle mentioned that you can use partial pressure in ice boxes, so you do not have to convert unless it asks.