Modifies a noun

• solution: I gave the shank a quick wipe down with potassium permanganate solution to make the patterns stand out.

• crystal: You might like to try growing sugar crystals, copper sulfate crystals, sodium silicate crystals, potassium permanganate crystals or iodine crystals.

• particle: Despite the evidence provided by the spreading purple color, the majority believe that the potassium permanganate particles should stay in one place.

Noun used with modifier

• potassium: I gave the shank a quick wipe down with potassium permanganate solution to make the patterns stand out.