Q.

Consider the fraction

X2Y(g) = X2(g)+12Y2(g)

The equation representing correct relationship between the degree of dissociation (x) of X2Y(g) with its equilibrium constant Kp is _______ .   

Assume x to be very small.                        [2025]

1 x=2Kp2p3  
2 x=Kp2p3  
3 x=Kpp3  
4 x=2Kpp3  

Ans.

(1)

X2Y(g)X2(g)+12Y2(g)t=0 (moles)a00t=∞ (moles)a(1-x)axax2t=∞ (mole fraction)a(1-x)a(1+x2)axa(1+x2)ax2a(1+x2)=(1-x1+x2)=(x1+x2)x2(1+x2)1xx2Partial pressures1×Px×Px×P2Total=a(1+x2)  


Kp=PX2×(PY2)1/2PX2Y=xP×(xP2)1/2P

Kp=x3/2P1/221/2

Kp2=x3P2

x=2Kp2P3