Question

please solve all parts

1. Zinc has been heavily used in the metal finishing industry and the typical wastewater from this industry contains Zn". When this untreated wastewater is discharged to the nature, zinc can be precipitate out with water as zinc hydroxide due to its low solubility product constant. Providing the value of solubility product constant of zinc (II) hydroxide as 3.0x10-16 (a) Write a chemical equation to represent the dissolution of zinc (II) hydroxide (2 point) (b) Determine the maximum concentration of zinc (II) ions in ppm of zinc) present in water from the dissolution of zinc (II) hydroxide. (3 points) (c) Determine the maximum pH of the solution resulting from the dissolution of zinc (II) hydroxide. (2 point) (d) The drinking water standard for zinc is 5 ppm. Use both Ksp value and Ksp expression to determine the zinc ion concentration in a water sample with a pH of 6.50 at 25°C. Will this water sample exceed the drinking water standard for zinc? (3 points) Hint: no ICE table needed (solving this problem with an ICE table will be marked wrong)

Answer 1

1 Ca) スれCOH)2 =スnt +2(OH)" 34 nC) yduoude 2(0H) 25 S CS=Maxumum concuntialion mol L) n () ons s.25)43 KAp=3.0 x io6 mol L 4.22 x10 S = g. L n2t t Rulaue atomic mass n5 274 3 xI0- mgL 0, 2143 ppm 374 3 Xio3 (Img.LP) Ce EOH poH Log Co pH14- poH 25 8.44 Xio mot.L- 5.07 8.93 Cd) PH= 6.50 pote 7.5 H 3. 16 xlo molL -I = 25 -S,58 x10 mot L 102.7g.L =102.7X10 mg. -5 a. 0o l02Y PPm Bub te duinkung wate landad, fo Zn is 5 ppm, マThis watu hample cuill NOT ud Atd

The above is a numerical problem related to the solubility and the solubility product of ternary ions.