1.8. Diffusion Coefficient

Try these first

1. 1.

   What is the diffusion coefficient?

   Hint

   Think about how diffusion represents the rate of spread of a substance.

2. 2.

   How does diffusion occur?

   Hint

   Consider the idea of spreading out evenly.

3. 3.

   What role does the diffusion coefficient (D) play in mass transfer?

   • It determines the temperature of the system.
   • It quantifies the rate of diffusion in relation to concentration gradients.
   • It measures the weight of a substance.

   Hint

   What does D correlate with in terms of concentration differences?

4. 4.

   True or False: Equilibrium in mass transfer means that substances are actively moving.

   • True
   • False

   Hint

   Think about whether movement continues when things are balanced.

5. 5.

   Calculate the diffusion coefficient for a chemical that moves through water at a rate of 0.5 kg/m²s with a concentration difference of 0.1 kg/m³ across a distance of 0.5 m.

   Hint

   Remember to set up the equation using Fick's law of diffusion.

6. 6.

   Discuss the environmental implications of a high diffusion coefficient in water pollutants.

   Hint

   Think about how rapidly a spill could affect aquatic life and ecosystems.