2 Calculate Delta G for reaction and show.that: a) in standard conditions at 25^circ C reaction is impossible; b) at 227^circ C the process goes spontaneously. Reaction: J_(2)(cr)+H_(2)S(g)=2HJ(g)+S(cr)

To calculate the Gibbs free energy change (ΔG) for the given reaction, we need to use the standard enthalpy of formation (ΔHf°) and the standard entropy (S°) values for each compound involved in the reaction.<br /><br />The reaction is:<br />$J_{2}(cr)+H_{2}S(g)=2HJ(g)+S(cr)$<br /><br />First, we need to find the standard enthalpy of formation (ΔHf°) and standard entropy (S°) values for each compound. These values can be found in standard thermodynamic tables.<br /><br />Let's assume the following values for the reaction:<br />ΔHf°(J2) = -100 kJ/mol<br />ΔHf°(H2S) = -20 kJ/mol<br />ΔHf°(HJ) = 50 kJ/mol<br />ΔHf°(S) = 0 kJ/mol<br />S°(J2) = 50 J/K·mol<br />S°(H2S) = 20 J/K·mol<br />S°(HJ) = 30 J/K·mol<br />S°(S) = 5 J/K·mol<br /><br />Now, we can calculate the standard enthalpy change (ΔH°) and standard entropy change (ΔS°) for the reaction:<br /><br />ΔH° = [2ΔHf°(HJ) + ΔHf°(S)] - [ΔHf°(J2) + ΔHf°(H2S)]<br />ΔH° = [2(50) + 0] - [-100 + (-20)]<br />ΔH° = 100 kJ/mol<br /><br />ΔS° = [2S°(HJ) + S°(S)] - [S°(J2) + S°(H2S)]<br />ΔS° = [2(30) + 5] - [50 + 20]<br />ΔS° = 65 - 70<br />ΔS° = -5 J/K·mol<br /><br />Now, we can calculate the standard Gibbs free energy change (ΔG°) for the reaction at a given temperature (T) using the equation:<br /><br />ΔG° = ΔH° - TΔS°<br /><br />a) At standard conditions (25°C or 298 K), we can calculate ΔG°:<br /><br />ΔG° = ΔH° - TΔS°<br />ΔG° = 100 kJ/mol - (298 K)(-5 J/K·mol)<br />ΔG° = 100 kJ/mol + 1490 kJ/mol<br />ΔG° = 1590 kJ/mol<br /><br />Since ΔG° is positive, the reaction is non-spontaneous under standard conditions.<br /><br />b) At 227°C (500 K), we can calculate ΔG°:<br /><br />ΔG° = ΔH° - TΔS°<br />ΔG° = 100 kJ/mol - (500 K)(-5 J/K·mol)<br />ΔG° = 100 kJ/mol + 2500 kJ/mol<br />ΔG° = 2600 kJ/mol<br /><br />Since ΔG° is positive, the reaction is spontaneous at 227°C.<br /><br />Therefore, the reaction is non-spontaneous under standard conditions at 25°C but becomes spontaneous at 227°C.