Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Redox for molybdenum

  1. Nov 28, 2004 #1


    User Avatar
    Science Advisor
    Gold Member


    Anyone know something about Molybdenum(V) ions?

    1n our university, we instruct an experiment to students, in which ammonium molybdate ([itex]\displaystyle (NH_4)_2MoO_4[/itex]) is reacted with tin chloride with hydrochloric acid. A redox reaction occurs, to my knowledge it should be like that:

    [tex]2(NH_4)_2MoO_4 + SnCl_2 + 12HCl \longrightarrow 2MoOCl_3 + SnCl_4 + 6H_2O + 4NH_4Cl[/tex]

    This reaction produces a blue colloidal solution, in which we are sure that molybdenum(V) ions are present. Is this compound the best stable molybdenum(V)-bearing one?

    Thank you.
  2. jcsd
  3. Nov 29, 2004 #2


    User Avatar
    Staff Emeritus
    Science Advisor

    Have you considered [tex]\displaystyle [NH_4]_2[MoCl_5(H_2O)][/tex]

    I could not find any information on heat of formation or stability, but I have seen this compound referenced.

    I also found a comment concerning [tex]Mo_2O_5 \cdot xH_2O[/tex] which states blue colloidal solution.
    Last edited: Nov 29, 2004
  4. Nov 30, 2004 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I think Mo(V) is among the least common of its oxid. states. 2, 3, 4 are more common, I think.

    However, I'm pretty sure Mo forms fairly stable pentahalides (MoCl5 for sure...and a few others too, I believe) because some of them get used for catalysis.

    So, in my opinion, MoCl5 is also a possibility in your reaction...but I have no idea what color that is.

    Is the blue colloid stable under heating ?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook