The Student Room Group

Color changes Transition metals-Unit 6 chemistry

Here is a picture of the question F818EDB7-D211-43B9-B5A2-C9D73D648838.jpeg
In part c
They add drops of KMnO4 to a solution which contains Fe2+ ions and they ask about the color change

When I read the question
I thought, the color change they want is the color change of the solution but turns out
They want the color change of the KMnO4 ( from the MS)
How can I tell ?
(edited 4 years ago)
Reply 1
You haven't attached a question.
Reply 2
Original post by memeking
You haven't attached a question.


Just did, sorry for the delay
Reply 3
Because you are adding the MnO4 to the solution in the flask, which is Fe2+. At the end it will be pink (Mn2+)
However, it you were to add the Fe2+ to the MnO4, the MnO4 would be purple, and at the end will be pink again (Mn2+).
Reply 4
But the answer in the mark scheme is purple to colorless .
shouldn’t the brown color of Fe3+ overpower any other color anyway ?
Original post by memeking
Because you are adding the MnO4 to the solution in the flask, which is Fe2+. At the end it will be pink (Mn2+)
However, it you were to add the Fe2+ to the MnO4, the MnO4 would be purple, and at the end will be pink again (Mn2+).

Quick Reply

Latest