Question

For a particular reaction, delta H is 67.6 kJ/mol and delta S is 126.9 J/(molk). Assuming these values change very little with temperature, over what temperature range is the reaction spontaneous in the forward direction?

The reaction is spontaneous for temperatures

less than? Greater than?

T= ???? K

Answer 1

delta G has to be negative for spontaneous reaction that is delta G < 0

                                                                                 deltaH-T*deltaS <   0

                                                                                  67.6*1000J - T* 126.9J < 0

                                                                                   so 67600   < T*126.9

                                                                                    so 67600/126.9    <   T

                                                                                         523.7   <T

                       So reaction to be spontaneous T >523.7 K