Question

: Discuss the possible reason(s) the food dyes diffuse to form distinct zones and do not immediately mix?

Answer 1

Diffusion

Explanation:

• Food coloring illustrates diffusion in water. Diffusion is the mixing of molecules due to their random motion, whether in a liquid or a gas.
• Because molecules in cold water have less kinetic energy than in warm water, the diffusion process is much slower than in warm water. But the food coloring can also show movement that isn't random, such as agitation of the water by convection.

• Diffusion does not require agitation, such as stirring, though agitation does speed the process.  
• In the case of food coloring in water, the water is the solvent while the food coloring is the solute.

• Once they've mixed, they make a solution. Diffusion takes time, though how much time depends on the kinetic energy of the molecules randomly bouncing among each other.

• This rand om bounc ing – called Browni an mo tion – results from the atoms vibrati ng, which they do fas ter and ha rder the hott er they are. The end result of these movements, over time, is the final, uniform solution.

• The food coloring has a slightly higher specific gravity, or relative density, than water, so before it has time to diffuse, it tends to sink in the water.

• When the water is cold, and the diffusion rate is slower, more of the food coloring stays together in a plume falling to the bottom of the container.  

• Left alone and undisturbed, it might form a layer at the bottom because of Brownian motion, though, there won't be a sharply defined boundary between the water and the coloring.
• The random motion of the molecules will gradually diffuse the color into the water. Agitation will speed the process of diffusion.