Using 1.0 times 10^-6 M as the criterion for quantitative removal, determine whe

Question

Using 1.0 times 10^-6 M as the criterion for quantitative removal, determine whether it is feasible to use SO_4^2- to separate Ba^2+ and Sr^2+ in a solution that is initially 0.040 M in Sr^2+ and 0.20 M in Ba^2+. SO_4^2- to separate Ba^2+ and Ag^+ in a solution that is initially 0.030 M in each cation. For Ag_2 SO_4, K_sp = 1.6 times 10^-5. OH^- to separate Be^2+ and Hf^4+ in a solution that is initially 0.030 M in Be^2+ and 0.020 M in Hf^4+. For Be(OH)_2, K_sp = 7.0 times 10^-22, and for Hf(OH)_4, K_sp = 4.0 times 10^-26. IO_3^-, K_sp =3.3 times 10^-11, and for TlIO_3, K_sp = 3.1 times 10^-6.

Explanation / Answer

a)

      Ksp, SrSO4 = 3.44x10-7

When BaSO4 completely precipitates ([Ba2+]= 1x10-6M),

[SO42-] must be   1.08x10-10/1x10-6M = 1.08x x10-4M

and [Sr2+] may be 3.44x10-7/1.08x x10-4M = 3.2x10-3M that is < 0.04 M

Conclusion : Sr2+ starts to precipitates before the quantitative removal of Ba2+ is completed. Answer:NO.

b. When BaSO4 completely precipitates ([Ba2+]= 1x10-6M),

[SO42-] must be 1.08x10-10/1x10-6M = 1.08x x10-4M

and [Ag+] may be (1.6x10-5/1.08x x10-4M)1/2 = 3.8x10-1M that is > 0.03 M

Conclusion : Ag+doesn’t starts to precipitates before the quantitative removal of Ba2+ is completed. Answer:YES.

c. When Be(OH)2 completely precipitates ([Be2+]= 1x10-6M),

[HO-] must be   (7x10-22/1x10-6M)1/2 = 2.6x x10-8M

and [Hf4+] may be 4x10-26/(2.6x x10-8)4 =8.7x104M that is > 0.02 M

Conclusion : Hf4+doesn’t starts to precipitates before the quantitative removal of Be2+ is completed. Answer:YES.

d. When In(InO3)3 completely precipitates ([In3+]= 1x10-6M),

[IO3-] must be ( 3.3x10-11/1x10-6M)1/3 = 3.2x x10-2M

and [Tl+] may be 3.1x10-6/3.2x x10-2 =1x10-4M that is < 0.1 M

Conclusion : Tl+ starts to precipitates before the quantitative removal of In3+ is completed. Answer:NO.

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.