All these are good questions that will test you on your basic concepts of this chapter on Redox Reactions.
5. When iron (III) sulphate is reduced to iron (II) sulphate, the colour of the solution turns from
A) brown to yellow
B) green to yellow
C) red to colourless
D) brown to greenAns: D
Looking forward to hearing to your answers.
Sean
Hey Lynn,
You are spot on.
Fe3+ salt solutions generally have brownish/yellowish colour whilst Fe2+ salt
solutions generally have greenish colour. As such, Iron(III) sulphate has brown
colour whilst Iron (II) sulphate has green colour.
Note:
Do not confuse this with the Precipitate that Fe2+ and Fe3+ salt solutions that
react with Sodium Hydroxide (as in the Qualitative Anaysis Test for Cations).
In such tests, upon reaction with Sodium Hydroxide, green ppt is observed due
to formation of Iron (II) Hydroxide and Yellowish brown ppt is observed for
formation of Iron (III) Hydroxides. You can memorise the similarity thou, since
only Fe2+ and Fe3+ has such distinct colors.
Cheers
Sean
This is a QA practical question.
Fe3+ is reddish brown
Fe2+ is dirty green.
I remember me and my friends like to joke about the dirty green color which somewhat reassembles the color of baby poo poo ….
haha…