The following reactions are important ones in catalytic converters in automobiles. Calculate Delta G for each at 298 K. Predict the effect of increasing temperature on the magnitude of Delta G.
2CO(g) + 2NO(g) -> N2(g) + 2CO2(g)
5H2(g) + 2NO(g) -> 2NH3(g) + 2H2O(g)
2H2(g) + 2NO(g) -> N2(g) + H2O(g)
To calculate Delta G (the change in Gibbs free energy) for each reaction, you'll need to know the standard Gibbs free energy, ΔG°, for each reaction and then use the equation:
ΔG = ΔG° + RT * ln(Q)
where ΔG is the Gibbs free energy, ΔG° is the standard Gibbs free energy, R is the gas constant (8.314 J/(mol*K)), T is the temperature in Kelvin, and Q is the reaction quotient.
The reaction quotient, Q, is determined using the concentrations of the reactants and products at a given temperature.
1. For the reaction: 2CO(g) + 2NO(g) -> N2(g) + 2CO2(g)
The standard Gibbs free energy, ΔG°, can be obtained from a thermodynamic table or calculated using standard enthalpy (ΔH°) and standard entropy (ΔS°) values.
Once you have ΔG°, you can substitute the values in the equation ΔG = ΔG° + RT * ln(Q) to calculate ΔG at 298 K.
2. For the reaction: 5H2(g) + 2NO(g) -> 2NH3(g) + 2H2O(g)
Follow the same procedure as above to calculate ΔG at 298 K.
3. For the reaction: 2H2(g) + 2NO(g) -> N2(g) + H2O(g)
Again, follow the same procedure as above to calculate ΔG at 298 K.
Now, regarding the effect of increasing temperature on the magnitude of ΔG, let's consider the equation ΔG = ΔG° + RT * ln(Q). As temperature increases, the term RT * ln(Q) becomes more significant. This is because the gas constant (R) and the natural logarithm (ln) are both positive values. Therefore, increasing temperature will increase the magnitude of ΔG.
In summary, to calculate ΔG for each reaction at 298 K, you need ΔG° values and the reaction quotient (Q). Increasing temperature will increase the magnitude of ΔG.