When Potassium permanganate a purple coloured solid substance is dissolved in water the colour of solution becomes purple because purple coloured particles of potassium permanganate spread throughout water making the whole water look purple.
Diffusion refers to the process by which molecules intermingle as a result of kinetic energy of random motion. The molecules of gases are in constant motion and make numerous collisions with each other.
Effusionis the escape of gas molecules through a tiny hole such as pinhole in a balloon.
All gases spontaneously diffuse into one another when they are brought into contact.
Diffusion into a vacuum will take place much more rapidly than diffusion into another place.
Both the rate of diffusion of a gas and its rate of effusion depend on its molar mass. Lighter gases diffuse faster than heavier gases. The gas with highest rate of diffusion is hydrogen.