Question

1)When delta G= 0; a system is at equilibrium. Use values for delta H and delta S to determine the temperature at which the following system would reach equilibrium.

N2(g)+ O2(g)--->2NO(g)

2)Complete te following table:

Enthalpy change delta H, Etropy change delta S, Predicted Sign for delta G.

+(positive) -(negatve) ?

+(positive) -(negative) ?

-(negative) -(negative) ?

-(negative) +(positive) ?

Answer 1

1)

DG = DH-TDS

DG = 0 (at equilibrium)

so

0 = DH-TDS

T = DH/DS

...............................................................................................

Use the eq. DG = DH -TDS

Enthalpy change delta H, Etropy change delta S, Predicted Sign for delta G.

+(positive) -(negatve) +(positive)   

+(positive) -(negative)    +(positive)

-(negative) -(negative)      AT low temperature -ve

                                                                                                 At high temperature +ve

-(negative) +(positive)    -ve(negative)