Diffusion of potassium permanganate, image 4 of 4. A piece of potassium permanganate was placed at the bottom of the beaker at 12 o'clock (6 hours ago). It has now diffused thoroughout the solution and turned the solution a deep purple colour. This indicates that the potassium permanganate is achieving a uniform concentration. Diffusion is random movement of molecules in solution eventually leading to a uniform concenteration of the molecules throughout the soultion. Diffusion always occurs from a region of high concentration to a region of low. For a sequence showing the diffusion, see A350/131, A350/132 and A350/133.