Australia's Science Forum

Hi
A teacher was collecting some puddle water and they added silver nitrate and the water turned pink.
Does anyone know what is in the water to make it go pink?

Thanks Superbug

Only thing I can think of would be cobalt - though why that would be in the puddle....??

[Co(H2O)6]2+(aq)(pink) + 4Cl-(aq) ⇌ [CoCl4]2-(aq)(blue) + 6H2O(l)

Removal of chloride ions through precipitation with silver nitrate would push equilibrium to the left.

Yes I Know. The teacher had no idea either.

Could the silver nitrate have been contaminated ? Just a thought

No I dont think so Smeee, as they used it for the other water samples collected.

wonder if the beaker was contaminated? could have been potassium permanganate