[cvn]

Hello.

I was trying to react Sulphuric Acid with Iron, when it gives a clear light green solution after the reaction completes. So i filtrate out, and leave it to stand.

After that, i found that the pale green solution turns orange solution. So i added iron and heat it. It turns back to a green solution.

Why did the solution turn orange in the first place? What reaction actually took place? Is it correct to reverse back to iron(II) sulphate by adding iron and heating it again?

thanks!

[AWK]

Iron(II) is oxidized by oxygen to iron(III), then reduced by metallic iron to Fe(II)

[cvn]

oh thanks!

i reduced it with metallic iron, and it get back to a clear green solution.

but then again, when i heat it to crystallise it, it changes its color back to orange, which turn back to iron(III) i guess.

so is there a way to get iron(II) sulphate salt? and not iron(III) compound?

thanks! 

[AWK]

Iron(II) sulfate is a very susceptible to oxidation by an air. The only way to get a relatively stable iron(II) sulfate is to mix it with ammonium sulfate in 1:1 molar ratio (Mohr salt). It can be crystallized as hydrate (FeSO4.(NH4)2SO4.6H2O).