Question

8. Sodium bicarbonate, NaHCO3, undergoes thermal decomposition according to the reaction: 2 NaHCO3 (s) + Na2CO3 (s) + CO2 (g) + H20 (g). How does the equilibrium position shift as a result of each of the following disturbances? a. 0.20 atm argon is added. b. NaHCO3 (s) is added. c. Mg(CIO)2 is added as a drying agent to remove H2O vapor. d. Dry ice (Solid CO2) is added. e. The volume of the container decreases. f. The temperature of the system increases. g. The pressure on the system decreases. 9. Calculate the (benzoic acid), CHCOOH, needed to provide a (H30'] of 3.5 x 104 M. The K of benzoic acid is 6.3 x 10 10. Calculate the pH of a 0.0225 M solution of NaOCN. The K, of HOCN = 3.3x104 11. a. If solid NH HS is placed in an evacuated flask at 250 °C, it will dissociate until the total pressure is 5.00x10 torr. Calculate the value of the equilibrium constants (kp and Kc) for the dissociation reaction: NH HS (s) (→ HS (8) + NH3(g). b. Additional NH, is introduced into the equilibrium mixture without a change in temperature until the partial pressure of NH3 is 7.00x10 torr. What is the partial pressure of H2S under these conditions? What is the total pressure in the flask? 12. Calculate Kc for the reaction: 2 NO> () N; (g) + 2 0, (g) using the following data: a. % N; (e) + %0 (g) <> NO (€) Kc = 4.8x10 10

Answer 1

& towards right (products). NaHCO₃(s) is added. Increase in NaHCO3 amount will shift the equilibrium towards right side or towards products. c. when Mg(clou) is added, the amount of to vapor will decrease, due to this the equilibrium will shift towards right side or towards products d. when dry ice is added CO₂ (9) increases, which shifts the equiliorium towards left side or towards reactants. (NaHCO,] increases when the volume of container decreases, equilibrium will shift towards the formation of NaHCO3

If. The given reaction is endothermic. when temperature of the system increases, formation of products is fowored. That is equilibrium will shift towards right side that is towards products. rohal g. The pressure is inversely proportional to volume. when pressure is decreased, then the volume will increase and the equilibrium will shift towards the species where there is an increase in number of moles. Hence, decrease in pressure shifts the equilibrium towards right side that is formation of NaCO3(s) and CO(g) and Ho (g) is favored.