Answer:
hot
Explanation:
Diffusion is a type of matter transport, and aims to promote a balance between two solutions that are, initially, with different concentrations. It is a physical phenomenon, where at the time of thermal energy the molecules move constantly in a fluid, which can be liquid or gas, promoting the passage of the solute to regions of lower concentrations.
The diffusion rate, in turn, refers to the speed of movement of these molecules. In hot solutions the molecules move at high speed, for this reason, in these substances the rate of diffusion is higher.
