Volume occupied by B atom =20% of total volume=20% of 22.7L=4.54L Remaining volume =(22.7−4.54)L=18.16LMole fraction of B=χB=22.74.54=0.2Mole fraction of B2=χB2=22.718.16=0.8Partial pressure of B=pB=0.2×1=0.2 barPartial pressure ofB2=pB2=0.8×1=0.8 bar Kp=pB2pB2=0.80.22=0.80.04=0.05