Question

Why chloroform is stored in dark coloured air tight bottles?

Answer 1

Chloroform (CHCl₃ ) when exposed to air and light forms a poisonous compound phosgene. So it is stored in cool and air-tight coloured bottles.

\[\ce{\underset{(Chloroform)}{2CHCl3} + O2 ->[sunlight]\underset{(Phosgene)}{2COCl2} + 2HCl}\]