Why do we store silver chloride in dark coloured bottles?

On exposure to sunlight, silver chloride disintegrates into silver and chlorine.

It really needs to be in dark glass, kept in a dark place (cabinet).

As an interesting story, my first year of teach quant I told the students there was no way of keeping that AgCl from turning purple and since exposure to ANY light made it change to Ag and caused low results for the gravimetric determination of Ag that the exposure should be kept to a minimum. After a day or two I saw, after doing this experiment my self for years and years, my first WHITE AgCl ( absolutely no purple). The students had taken me at my word and covered the filters, the pptn vessels and any other glassware used with any kind of opaque material they could find. No light got in, no decomposition took place, and pure white AgCl resulted.

We store silver chloride in dark colored bottles to prevent it from undergoing decomposition or degradation caused by exposure to light. Light, particularly ultraviolet (UV) light, can initiate a photochemical reaction in silver chloride, breaking it down into silver metal and chlorine gas. This reaction is known as photolysis. The dark-colored bottles serve as a protective barrier, reducing the amount of light that reaches the silver chloride and minimizing the chances of decomposition.

If you're curious how this information is obtained, it can be found through various scientific studies and experiments. Researchers analyze the behavior of different substances under different conditions, including exposure to light. Through these experiments, they observe the changes that occur in silver chloride when exposed to various light sources. They also analyze the impact of different factors, such as the intensity and wavelength of light, on the decomposition process. Based on their findings, they recommend appropriate storage conditions for silver chloride and other similar compounds to ensure their stability.