Question

Why are certain reagents like silver bromide stored in dark bottles?

Answer 1

Reagents like silver bromide are light-sensitive compounds; hence, they are stored in dark bottles because it easily decomposes in the presence of light to form silver metal and bromine gas. The black bottles doesn't allow light to penetrate thus preventing oxidation of the reagent. This is why silver bromide is stored in dark bottles in labs to prevent them being oxidised.