Why is chloroform stored in dark coloured bottles ?

Explanation

Because it reacts with oxygen of air in the presence of sunlight to give phosgene, a poisonous gas. Thus, to protect it from sunlight, it is stored in dark brown bottles
` underset("Chloroform ")(CHCl_3) + 1//2O_2 overset("sunlight")to underset("phosgene")(COCl_2) +HCl`