colours of iron (II) nitrate, iron (III) nitrate and copper nitrate (1 Viewer)

[Dyldodeath]

hey
iam finding that its very hard to determine the colour that iron (II), iron (III) and copper cations will go when e.g. barium nitrate is added (bascially a nitrate is added). i chose barium because it has low electronegativity so it should be reactive

my belief is that copper nitrate is blue
iron (II) and iron (III) are brown and green respectively or something similar

maybe if you use nitrate to distinguish between copper and the irons, you could then use potassium ferricyanide to distinguish between iron (II) and iron (III)

any thoughts?

p.s. i cant use hydroxide
cheers

 

[nat_doc]

all nitrates are soluble so ... copper nitrate has no colour. u can use a flame test. copper is a pale blue colour

 

[Toranilor]

You can also use potassium permangenate (K4MnO4) to distinguish betw Iron (II) and Iron (III), as Iron (II) will change it from purple to clear.

Oh, and I'm not sure if it will work, but you could try increasing the alkalinity of the solutions with ammonia to try and 'cheat' some [OH] out of the water in the solution.