Calculating Diffusion: How Long Does Glucose Diffusion Take?

We can use $x_{\text{rms}}=\sqrt{2D\text{t}}$, the expression for the average distance moved in time $t$, and solve it for $t$. All other quantities are known.

Solving for $t$ and substituting known values yields

This is a remarkably long time for glucose to move a mere centimeter! For this reason, we stir sugar into water rather than waiting for it to diffuse.