An increase in temperature increases the average kinetic energy of the coloring molecules.
The faster spreading of the food coloring at a higher temperature follows the kinetic theory of molecules.
According to the theory, the average kinetic energy of molecules depends on their temperatures. Thus, the more their temperatures, the faster they move.
This means that the molecules of the food coloring spread faster at 70°C because they move faster as a result of the higher temperature - unlike those at 4°C
More on the kinetic theory of molecules can be found here: https://brainly.com/question/15013597
