tailieunhanh - An Introduction to Thermodynamics phần 9

Chếch tiếp tục phân hủy, những nồng độ, sẽ gây ra không có sự thay đổi trong năng lượng tự do, không có xu hướng phân hủy hơn nữa bởi vì hệ thống hiện tại là trạng thái cân bằng. Một hằng số cân bằng cho phản ứng liên quan đến khí, | How does this K compare with the K from part a c. If 1 atm of HI at 250oc is placed in a vessel and allowed to reach equilibrium with its decomposition products at this temperature what will be the final pressure of HI 10. The solubility product constant Ksp for MgF2 at room temperature is x 10-9 Assuming activity coefficients are unity find the solubility of MgF2 a. in water b. in MNaF solution Addition of ions to a dilute solution will decrease the values of activity coefficients. Would the addition of Na2SO4 increase or decrease the solubility of MgF2 11. Find AG0 for the process of dissolving MgF2 in water. Is this positive or negative Explain why in terms of what will happen when MgF2 is added to water. 12. The solubility products for barium oxalate at 18oC are given below. A BaC2O4-2 H2O Ksp x 10-7 B Bac2o4v2 H2O Kp x 10-7 a. Assuming only A is present in the solid phase find the concentration of Ba ion in aqueous solution in equilibrium with this solid. b. Assuming only B is present in the solid phase find the concentration of Ba ion in aqueous solution in equilibrium with this solid. c. Describe what will happen if 1 g of A and 1 g of B are added to 100 ml of water at 18oc under 1 atm pressure. d. How many phases will be present at equilibrium What are they 13. The dissociation constant of H2S in water solution is x 10-8. H2S - H HS- The second dissociation to give S can be ignored here. Find the concentration of hydrogen ion in M H2S solution. 14. The dissociation constant of benzoic acid is x 10-5 at 25oc. Find the concentration of hydrogen ion a. in M benzoic acid solution b. in solution containing M benzoic acid plus M sodium benzoate. Benzoic acid dissociates to give one hydrogen ion BH----B- H . 15. For the cell Zn Zn a Ag a Ag a. Write the over-all cell reaction. b. What is E c. What is E d. Is the reaction spontaneous 16. Find the equilibrium constant for the reaction at 25oC 7 10 07 4- 105 2 .