Tyndall effect with sodium thiosulfate скачать в хорошем качестве

Tyndall effect with sodium thiosulfate

Tyndall effect is scattering of light caused by particles with large sizes compared to the wavelength of light, such as dust or fog. It is contrasted to Rayleigh scattering, where the particles are small compared to the wavelength. With both effects, the blue light is scattered more, while red light is mostly transmitted, as shown in this experiment with a flashlight shining through a tray with a cloudy solution. The solution in the tray initially consists of 1 L of water and 20-25 grams of sodium thiosulfate pentahydrate (Na2S2O3·5H2O). The reaction is initiated by adding a second solution obtained by dissolving 0.15 grams of concentrated sulfuric acid (H2SO4) in 10-60 mL of water. As colloidal sulfur slowly forms in the solution, the colours of transmitted and scattered light progressively saturate towards transmitted orange, similar to a sunset, and scattered blue, similar to the colour of the sky. Eventually, the solution becomes cloudy enough to block almost all transmitted light.