Chemistry

Can somebody this explain this observation:

Fe3+ + SCN- > FeSCN2+

Solution A: 3 ml 0.1 M KSCN samt 3 ml 0.1 M FeNO3 is mixed and diluted 20 times

Four test tubes

1) To 5 ml of sol A is 1 ml FeNO3 added.
2) To 5 ml of sol A is 1 ml KSCN added.
3) To 5 ml of sol A is 1 ml 6 M NaOH added.
4) Reference

Why is testtube 1 less red than 4 och why is testtube 2 more red than 4?

I'm grateful fore answer :)

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1) To 5 ml of sol A is 1 ml FeNO3 added.
2) To 5 ml of sol A is 1 ml KSCN added.
3) To 5 ml of sol A is 1 ml 6 M NaOH added.
4) Reference

In 1) your complex is [FeSCN]2+ which is less red

In 2) you have [Fe(SCN)3] which is redder.

Thank You!

So I do have several types of complexes.
Is it cumalative, can the metall ions take up different numbers of SCN-

Best regards Konrad

With Thiocyanate you have all those complexes (mono-, di-, tri-thiocyanato) depending on the concentration. We talked about that in a lab recently.

With ammonia for example it wouldn't work. There you can only have tetrammin and hexammin complexes.

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