Question

The synthesis of nh3 gas, which has δhof, = - 46.1 kj/mol and δgof, = - 16.5 kj/mol takes place during the reaction: n₂ (g) 3h₂ (g) → 2nh₃(g)

(a ) use only these data to calculate δho and δso for the reaction at 25°c.

Answer 1

The change in enthalpy, ΔHo, and the change in entropy, ΔSo, for the reaction can be calculated using the standard enthalpy of formation and standard Gibbs free energy of formation values. The equation shown is: N₂(g) + 3H₂(g) → 2NH₃(g). To calculate ΔHo, we can use the enthalpy of formation values for the reactants and products. Similarly, the change in entropy, ΔSo, can be calculated using the standard entropy values for the reactants and products.

Step-by-step explanation:

The change in enthalpy, ΔHo, and the change in entropy, ΔSo, for the reaction can be calculated using the standard enthalpy of formation and standard Gibbs free energy of formation values. The equation shown is:

1. N2(g) + 3H2(g) → 2NH3(g)

To calculate ΔHo, we can use the enthalpy of formation values for the reactants and products:

1. ΔHf(N2) = 0 kJ/mol
2. ΔHf(H2) = 0 kJ/mol
3. ΔHf(NH3) = -46.1 kJ/mol

Using the stoichiometric coefficients in the balanced equation, we can calculate the change in enthalpy:

1. (2 × ΔHf(NH3)) - (1 × ΔHf(N2) + 3 × ΔHf(H2))

Similarly, the change in entropy, ΔSo, can be calculated using the standard entropy values for the reactants and products:

1. So(N2) = 191.6 J/(mol·K)
2. So(H2) = 130.7 J/(mol·K)
3. So(NH3) = 192.8 J/(mol·K)

Using the stoichiometric coefficients in the balanced equation, we can calculate the change in entropy:

1. (2 × So(NH3)) - (1 × So(N2) + 3 × So(H2))