Equilibrium
- Which one of the following statements is not correct ? Answer: 1. The value of equilibrium constant is changed in the presence of a catalyst in the reaction at equilibrium. Key idea: a catalyst c... 1
- A 20 litre container at 400 K contains CO_2(g) at pressure 0.4 atm and an excess of SrO (neglect the volume of solid SrO). The volume of the container is now decreased by moving the movable piston fitted in the container. The maximum volume of the co… Answer: 4. 5 litre Key idea: for SrCO₃(s)⇌ SrO(s)+CO₂(g) , K_p = p_(CO_2) at equilibrium, so the maximum pressure of CO₂ is 1.6 atm. Initial... 1
- The percentage of pyridine (C_5H_5N) that forms pyridinium ion (C_5H_5N^+H) in a 0.10 M aqueous pyridine solution (K_b for C_5H_5N = 1.7×10^-9) is Answer: 1. 0.013% Key idea: for a weak base, α=√(K_b/C) . α=sqrtfrac1.7×10⁻⁹0.10=sqrt1.7×10⁻⁸=1.3×10⁻⁴ Percentage = 1.3×10⁻⁴×100=0.013% . 1
- The solubility of AgCl (s) with solubility product 1.6×10^-10 in 0.1 M NaCl solution would be Answer: 1. 1.6×10⁻⁹ M Key idea: the common ion Cl^- from NaCl suppresses the solubility of AgCl. Let solubility be s . [Ag^+]=s , [Cl^-]≈ 0.... 1
- MY and NY_3, two nearly insoluble salts, have the same K_sp values of 6.2×10^-13 at room temperature. Which statement would be true in regard to MY and NY_3 ? Answer: 2. The molar solubility of MY in water is less than that of NY₃ . Key idea: compare solubilities from the K_sp expression for each s... 1