I mixed the potassium permanganate solution with a toilet cleaner and got a paste like liquid, after

The yellow-black object is MnO2

Toilet cleaner core masterbatch + hydrochloric acid (about 21% hydrochloric acid) + water + preservatives + flavor + pigment = toilet cleaner.

2KMnO4+16HCL (concentrated) ==2KCL+2MnCL2+5CL2 +8H2O

Once KMnO4 is excessive, it will oxidize the MnCl2 generated by the previous reaction to MnO2 precipitate

2KMnO4 + 3MnCl2 + 2H2O = 5MnO2 +2KCl + 4HCl This reaction is the root cause of MnO2.

However, due to the insufficient contact between the reaction solution and potassium permanganate on the test tube wall, part of the MnCl2 is oxidized to form a precipitate attached to the test tube wall.

At this time, washing with a brush is not clean and will wear out the test tube... Just add an appropriate amount of toilet detergent to the test tube and heat it. Soon, those precipitates will dissolve, and there will be nothing left.

MnO2 + 4HCl (concentrated) = heating = = MnCl2 + 2H2O + Cl2

The main active ingredient of toilet cleaner is hypochlorous acid, potassium permanganate and hypochlorous acid react to form manganese chloride.

The paste liquid is most likely unique to the toilet cleaner and has nothing to do with the chemical reaction. I've tried, and that thing doesn't affect the reaction.

The main ingredient of toilet cleaner is acid, which is generally hydrochloric acid, so it should be manganese chloride.