[Knoton]

Does anyone know the redox reaction equations for the reaction between (NH4)6Mo7O24:4H20(Ammonium Molybdate), SnCl2:2H20(Stannous Chloride), and Phosphate that forms Molybdenum Blue(Mo5O14)?The Molybdate solution contains Sulphuric Acid. Also the Stannous Chloride is dissolved in glycerin

[Albert]

I don't think you should consider stannous chloride.

Try to write the chemical equation (what you have worked out so far, at least) and we'll begin to help you.

[AWK]

There are two reaction: non-redox formation of phosphomolybdic acid H3PMo12O40 in acidic medium((HCl) followed by reduction  to Mo5O15 after addition of  SnCl2 to this mixture.
(NH4)6Mo7O24 + Na2HPO4 + HCl = H3PMo12O40 + NH4Cl + NaCl
H3PMo12O40 +SnCl2 + HCl = Mo5O14 + SnCl4 + H3PO4 + H2O
Try to balance above reactions

[Knoton]

How would these reactions change if the acid used was H2SO4?

[AWK]

It is just acid, like HCl. In the second reaction may be a propblem with mixture SnCl4 and Sn(SO4)2

[Knoton]

I am having trouble balancing the first reaction(I haven't tried the second yet)
This is my best guess so far
12(NH₄)₆Mo₇O₂₄+7PO₄^-3+21H⁺=7H₃PMo₁₂O₄₀+6NH₄⁺
and at this point I get stuck because I can't balance the oxygens.

[Albert]

I have always written the equation for this test as follows:

3NH₄⁺ + 12MoO₄^2- + PO₄^3- + 24H⁺ -> (NH₄)₃PO₄.12MoO₃ + 12H₂O

 

[Knoton]

I have always written the equation for this test as follows:

3NH₄⁺ + 12MoO₄^2- + PO₄^3- + 24H⁺ -> (NH₄)₃PO₄.12MoO₃ + 12H₂O

 

How does this:12MoO₄^2-
Come from this:(NH₄)₆Mo₇O₂₄
Also, does the dot between the ammonium phosphate and the 12MoO₃ mean something? Is it complexing with it?

[AWK]

12(NH4)6Mo7O24 + 7Na2HPO4 + 86HCl = 7H3PMo12O40 + 72NH4Cl + 14NaCl + 36H2O