A 0.1 molar solution of K4[Fe(CN)6] is 46% ionised at 18°C. Calculate its osmotic pressure
Answers
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Homework Set 2.1 Solutions
Ch. 6: 8, 15-17, 19, 23, 25, 33, 36, 44, 49
8. For the reaction HCO3- ↔ H+ + CO32-, ΔG° = +59kJ/mol at 298.15K. Find the value of K for the reaction.
K = exp(-ΔG°/RT) = exp(-59000 J mol-1/(8.314 J mol-1 K-1*298.15 K)) = 5 x 10-11.
15. What concentration of Fe(CN)64- (ferrocyanide) is in equilibrium with 1.0 μM Ag+ and Ag4Fe(CN)6(s). Express your answer with a prefix from table 1-3.
Since it states “in equilibrium with”, no ICE table is needed.
Ksp = [Ag+]4[Fe(CN)64-] = 8.5 x 10-45 = (1.0 x 10-6)4*x
x = 8.5 x 10-45/1.0 x 10-24 = 8.5 x 10-21 M = 8.5 zM = [Fe(CN)64-]
16. Find [Cu2+] in a solution saturated with Cu4(OH)6(SO4) if [OH-] is fixed at 1.0 x 10-6 M. Note that Cu4(OH)6(SO4) gives 1 mole of SO42- for 4 mol Cu2+.
Cu4(OH)6(SO4)(s) ↔ 4Cu2+ + 6OH- + SO42- Ksp = 2.3 x 10-69
Initial 0 1.0 x 10-6 0
Change +4x +6x +x
Equilibrium 4x 1.0 x 10-6 +x (1.0 x 10-6 is fixed)