Question

Iminodiacetic acid (IDA) is often used in ion exchange resins as a way to remove heavy metals from industrial waste waters. It forms a 2:1 complex with many heavy metals, with a high selectivity for divalent over monovalent ions.

A 28.00 mL sample of 0.0300 M Ni2+ was added to 28.00 mL of 0.162 M iminodiacetic acid (the completely protonated form is abbreviated as H3A+) buffered at pH 7.00. Given that ?A2− is 4.6×10−3 at pH 7.00, what is the final concentration of Ni2+ remaining in solution?

Iminodiacetic acid (IDA) is often used in ion exchange resins as a way to remove heavy metals from industrial waste waters. It forms a 2:1 complex with many heavy metals, with a high selectivity for divalent over monovalent ions 2+ A 28.00 mL sample of 0.0300 M Ni was added to 28.00 mL of 0.162 M iminodiacetic acid (the completely protonated form is abbreviated as HA*) buffered at pH 7.00. Given that a2- is 4.6 x 10-3 at pH 7.00, what is the final concentration of Ni2+ remaining in solution? Ni2+(aq)2 A2-(aq)NiA(aq) Kf 2.00 x 1014 [Ni2+] 0.0148

Answer 1

page :01 Answeni- According to the given informatics to determine the final concentration of Ni 2+. Given, pH 7.00 ding=466 X103 Kf = 200x104 Let, insteal moles of AB 28 X 0.162 X PAR- = 28 X0.162 X 0.0046 OD 2086 initial millimoles of No 2t - 28 0.0300 = 0.84 teackon is Initial . Niate + Racaq) = Nita car). 0.84 0.020660 -2X + (0.84-4) (0.02086 - au) 2 -X change Equqlebrium

pagetoa athen, Kp = [NTAS (niat] [43]? axl04 (0.84-8)(0.02086 -22) io X22084 4.68X104 - (4.351x104+ux -0.083448) 4.351X04 + 4x -0.083444 = 0.5958 x 10"X 0.08304_>0.5952X1644. ux-8.08zuur + 40 3518104 ao by veing; b = bac w = 0.08344 Jo.083441-4 LUX 4.351x104) 20 ах ч *: 0.08344 J 6.963X163 - 1684.351X164 x= 0.08344 +6.963x103 – 609616X103

page:03 0.08344 + 101832 XOS 20 00846236 x = 0.01058 thenefore, mittimoles of Ni at left = 0.84 -0.01058 7 0.82902 :: [N: 24]: 018 2942 16 +16 0:82942 32 0.02591 M 1.: (N;2+] = 0.0259111