Question

why to we kept silver chloride in dark colour bottles

Answer 1

And dark coloured objects/bottles obstruct light.to prevent it from reacting, its stored in dark colored bottles as ,by keeping in this sunlight won't be able to reach silver chloride. It decomposes in the presence of light to form silver ( grey in colour ) and chlorine.

Answer 2

We store silver chloride in darkcoloured bottles in order to protect it from the effect of sunlight. Sunlight can decompose silver chloride and make it silver and chlorine. ... Compounds Like Silver Chlorideare light sensitive. And they may react to light very fast and lose its properties.