Q.

Consider the following equilibrium,  

CO(g)+2H2(g)CH3OH(g)

0.1 mol of CO along with a catalyst is present in a 2 dm3 flask maintained at 500 K. Hydrogen is introduced into the flask until the pressure is 5 bar and 0.04 mol of CH3OH is formed.  The Kp0 is ______ ×10-3 (nearest integer).  

Given : R = 0.08 dm3 bar K-1 mol-1  

Assume only methanol is formed as the product and the system follows ideal gas behaviour.             [2025]


Ans.

(74)

CO(g)+2H2(g)CH3OH(g)t=0 (moles)0.1x0t=∞ (moles)0.1-yx-2yy

As moles of CH3OH=y=0.04 mol

CO(g)+2H2(g)CH3OH(g)t=∞ (moles)0.1-0.04x-0.080.04=0.06

Total moles = 0.06+x-0.08+0.04=(0.02+x) mol

By ideal gas equation at equilibrium:

PV=nRT

5×2=(0.02+x)×0.08×500

x=0.23mol

Thus:

CO(g)+2H2(g)CH3OH(g)t=∞ (moles)0.060.23-0.08=0.150.04t=∞ (mole fraction)6251525425t=∞ (partial pressure)625×5=651525×5=3425×5=45Total=0.25


Kp=PCH3OHPCO×(PH2)2=4/5(65)×(3)2=74×10-3