Consider an electrochemical cell: A(s)|A^(n+)(aq,2M)||B^(2n+)(aq,1M)|B(s). The value of DeltaH^(theta) for the cell reaction is twice that of DeltaG^(theta) at 300K. If the emf of the cell is zero, the DeltaS^(theta) (in KJ^(-1)mol^(-1)) of the cell reaction per mole of B formed at 300 K is ________ (Given: ln (2)=0.7, R (universal gas constant)=8.3 JK^(-1)mol^(-1). H,S and G are enthalpy, entropy an Gibs energy, respectively).

Consider an electrochemical cell: A(s)|A^(n+)(aq,2M)||B^(2n+)(aq,1M)|

1.	Consider an electrochemical cell: A(s)\|A^(n+)(aq,2M)\|\|B^(2n+)(aq,1M)\|B(s). The value of DeltaH^(theta) for the cell reaction is twice that of DeltaG^(theta) at 300K. If the emf of the cell is zero, the DeltaS^(theta) (in KJ^(-1)mol^(-1)) of the cell reaction per mole of B formed at 300 K is ________ (Given: ln (2)=0.7, R (universal gas constant)=8.3 JK^(-1)mol^(-1). H,S and G are enthalpy, entropy an Gibs energy, respectively).
Answer» Solution :`(-11.62)` `underset(DELTAH^(o)=2DeltaG_(O)^(o))(A(s)\|A^(+n)(aq,2M))\|\|B^(+2N)underset(E_(cell)=0)((aq,1M)\|B(s))` Cell Rx `[AtoA^(+n)+ n e^(-)]xx2` `B^(+2n)+2n e^(-)toB(s)` `2A(s)+underset(1M)(B^(+2n))(aq)tounderset(2M)(2A^(+n))(aq)+B(s)` `DeltaG=DeltaG^(o)+RT" ln "([A^(+n)]^(2))/([B^(+2n)])` `DeltaG^(o)=-RT" ln "([A^(+n)]^(2))/([B^(+2n)])=-RT.ln(2^(2))/(1)=-RT.ln4` `DeltaG^(o)=DeltaH^(o)-TDeltaS^(o)` `DeltaG^(o)=2DeltaG^(o)-TDeltaS^(o)` `DeltaS^(o)=(DeltaG^(o))/(T)=-(RTln4)/(T)=-8.3xx2xx0.7=-11.62J//K.mol`