In the gaseous reactiojn 2A+B = A2B, Gibbs free energy=1200cal at 227Degree Celsius. What total pressure would be necessary to produce 60% conversion of B into A2B when 2:1 mixture is used? Ans (5.02atm) Sir, it is the question of Modern Approach To chemical calculations by Ramendra c. Mukerjee, page no.507, Q.no.31.

delG = -RT ln K.

Find out K

initially:

say x moles of B is present, then 2x moels of A is present. Let total pressure be P.

Finally:

say a moles of B reacted. Then. 2a mol of A reacts and a mol of A2B is formed.

given : a=0.6x.

Hence, B- 0.4x and A - 1.2x and A2B= 0.6x

partial pressure of A2B is (0.6/(0.6+1.2+0.4))*P = (0.6/2.2)P

similarly P_b = (0.4/2.2)P, P_a = (1.2/2.2)P

K_p = P_a2b / P_b .P_a ²    This value of Kp is obtained using the topmost formula. From this find out the value of P and that is the required value