Question

Prepare a flowchart for the separation of Pb²⁺, Zn²⁺, Ba²⁺, Mn²⁺, and Al³⁺.

Answer 1

The groups:

Group 1 = Pb

Group 2 = NONE

Group 3 = Zn, Mn, Al

Group 4 = Ba

Group1.

Add HCl, then precipitate Pb+2 ad PbCl2

Pb+2 + 2Cl- --> PbCl2

Group 2.

No reactions; but we need to add HNO3 (nitric acid)

Group 3.

Add NH3

Zn(NO3)2 + 2 (NH4)2S --> ZnS(s) + 2 NH4NO

Mn(NO3)2 + 2 (NH4)2S --> MnS(s) + NH4NO3

2 Al(NO3)3 + 3 (NH4)2S + 6 H2O --> 2 Al(OH)3(s) + 6 NH4NO3 + 3 H2S

For Mn...

2 Mn(NO3)2 + 5 NaBiO3 + 16 HNO3 --> 2 HMnO4 + 5 Bi(NO3)3 + 5 NaNO3 + 7 H2O

Time to add NaOH

Zn(OH)2(s) + 2 NaOH   --> Na2[Zn(OH)4]

Al(OH)3(s) + NaOH   --> Na[Al(OH)4](s) presence

Group 4.

For Barium; add NH42CO3

carbonate presence will precipitate Barium

Ba(NO3)2 + (NH4)2CO3  BaCO3(s) + 2 NH4NO3