188 DIY Science: Illustrated Guide to Home Chemistry Experiments
oALIpToN ACTIvITIES
If you have extra time, consider performing this optional activity:- Potassium permanganate has many uses, nearly all of which are based on the
fact that it is an extremely strong oxidizer. You can demonstrate this by placing
several layers of filter paper or paper towel in the bottom of a Petri dish or large
beaker and pouring the excess 0.01 M potassium permanganate solution you
prepared for this lab onto the paper. Initially, the paper will have the strong
violet color of the permanganate ion (+7). As the permanganate ion oxidizes
the cellulose in the paper, it is reduced from the +7 oxidation state to the green
+6 oxidation state. If you allow the reaction to continue long enough, the +7
permanganate ion is eventually reduced to the +4 state as orange/brown
manganese dioxide (MnO 2 ).
RQEWEvI UESTIOnS
q 1 : What are the final oxidation states of manganese in test tubes A, B, C, and D?
q: 2 What are the oxidation states of each atom in the following species: NH 3 , H 2 O, H 2 O 2 , K 2 Cr 2 O 7 , NaNO 3 , FeCl 2 , and AgNO 3?