Uploaded March 2025 | Updated September 2026, 2 weeks ago
In this experiment, we observe the diffusion of two substances towards one another:
🔬 Substances Used:
Potassium thiocyanate (KSCN)
Iron(III) nitrate (Fe(NO₃)₃)
At the start of the video, crystals of each substance dissolve on opposite sides of a water droplet. As they diffuse and meet, they react to form a striking blood-red complex ion:
🧪 Reaction Equation:
Fe³⁺ + SCN⁻ → FeSCN²⁺
Interestingly, the red color does not appear exactly in the middle. This is because Fe³⁺ (on the right) diffuses more slowly than thiocyanate (SCN⁻) on the left. While diffusion rates can be influenced by multiple factors—including interactions with surrounding water molecules and ions—on a simple level, Fe³⁺ is heavier than SCN⁻, which affects its movement.
This video is a fascinating demonstration of chemical kinetics and ion diffusion in action!
👍 If you found this interesting, don’t forget to like, subscribe, and share for more chemistry experiments!
In this experiment, we observe the diffusion of two substances towards one another:
🔬 Substances Used:
Potassium thiocyanate (KSCN)
Iron(III) nitrate (Fe(NO₃)₃)
At the start of the video, crystals of each substance dissolve on opposite sides of a water droplet. As they diffuse and meet, they react to form a striking blood-red complex ion:
🧪 Reaction Equation:
Fe³⁺ + SCN⁻ → FeSCN²⁺
Interestingly, the red color does not appear exactly in the middle. This is because Fe³⁺ (on the right) diffuses more slowly than thiocyanate (SCN⁻) on the left. While diffusion rates can be influenced by multiple factors—including interactions with surrounding water molecules and ions—on a simple level, Fe³⁺ is heavier than SCN⁻, which affects its movement.
This video is a fascinating demonstration of chemical kinetics and ion diffusion in action!
👍 If you found this interesting, don’t forget to like, subscribe, and share for more chemistry experiments!
