all 5&6 5.) Solid silver bromide , AgBr, can be dissolved by adding concentrated aqueous ammonia to give the water- soluble silver-ammonia complex ion. AgBr(s) + 2NH,(aq) U Ag(NH), (aq) + Br(a...
5.) Solid silver bromide , AgBr, can be dissolved by adding concentrated aqueous ammonia to give the water- soluble silver-ammonia complex ion. AgBr(s) + 2NH,(aq) U Ag(NH), (aq) + Br(aq) (a) Show that this equation is the sum of two other equations, one representing the dissolution of AgBr into its component ions and the other representing the formation of the silver-ammonium complex from silver ion and ammonia (b) Calculate the equilibrium constant for the above reaction K,(AgBr) = 5.0 x 10". K, (Ag(NH),')= 1.7 x 10 (c) A saturated solution is prepared by adding AgBr to a 2.0 NM solution of NH,. What are the concentrations of Ag(NH and Br when the system reaches equilibrium? 6.) (Taken from Chemistry ,8° Ed. by Chang) Phenolphthalein is the common indicator for the titration of a strong acid with a strong base (a) If the pKa of phenolphthalein is 9.10, what is the ratio of the nonionized form of the indicator (colorless) to the ionized form (reddish-pink) at pH 8.00? (b) If 2 drops of 0.060 M phenolphthalein are used in a titration involving a 50.0 mL volume, what is the concentration of the ionized form at pH-8.00? (Assume that 1 drop 0.050 mL)
5.) Solid silver bromide , AgBr, can be dissolved by adding concentrated aqueous ammonia to give the water- soluble silver-ammonia complex ion. AgBr(s) + 2NH,(aq) U Ag(NH), (aq) + Br(aq) (a) Show that this equation is the sum of two other equations, one representing the dissolution of AgBr into its component ions and the other representing the formation of the silver-ammonium complex from silver ion and ammonia (b) Calculate the equilibrium constant for the above reaction K,(AgBr) = 5.0 x 10". K, (Ag(NH),')= 1.7 x 10 (c) A saturated solution is prepared by adding AgBr to a 2.0 NM solution of NH,. What are the concentrations of Ag(NH and Br when the system reaches equilibrium? 6.) (Taken from Chemistry ,8° Ed. by Chang) Phenolphthalein is the common indicator for the titration of a strong acid with a strong base (a) If the pKa of phenolphthalein is 9.10, what is the ratio of the nonionized form of the indicator (colorless) to the ionized form (reddish-pink) at pH 8.00? (b) If 2 drops of 0.060 M phenolphthalein are used in a titration involving a 50.0 mL volume, what is the concentration of the ionized form at pH-8.00? (Assume that 1 drop 0.050 mL)