Chloroform is stored in dark coloured bottles. Explain in not more than two sentences.

Explanation

In the presence of light, chloroform is oxidised to a highly poisonnous gas phosgene.
`underset("Chloroform")(2CHCl_(3))+underset((Air))(O_(2))overset(light)tounderset("Phosgene")(2COCl_(2))+2HCl`
In order to check this, chloroform must be kept in dark brown coloured bottles. Moreover, te bottles must be completely filled and well stoppered to check the entry of air.