From the data given in Exercise 72, estimate a value of r S at 298 K for the reaction Exercise 72 Sodium carbonate, an

From the data given in Exercise 72, estimate a value of Δ_rS° at 298 K for the reaction

Exercise 72

Sodium carbonate, an important chemical used in the production of glass, is made from sodium hydrogen carbonate by the reaction

Data for the temperature variation of K for this reaction are K = 1.66 x 10^-5 at 30 °C; 3.90 x 10^-4 at 50 °C; 6.27 x 10^-3 at 70 °C; and 2.31 x 10^-1 at 100 °C.

(a) Plot a graph similar to Figure 13-10, and determine Δ_rH° for the reaction.

(b) Calculate the temperature at which the total gas pressure above a mixture of NaHCO₃(s) and Na₂CO₃(s) is 2.00 bar.

Figure 13-10

2 NaHCO3(s) Na2CO3(s) + HO(g) + CO2(g)