Analysis of the Halogenated Ethers

The ether is decomposed by water and the formaldehyde obtained is titrated iodometrically  

0-I-0-I5 gm. of the substance to be examined is weighed into a glass bulb which is then placed in a flask containing loo ml. water. After closing the flask with a stopper the bulb is broken, and the whole allowed to stand for 2-3 hours. 40 ml. N/io iodine solution are added from a burette and then an aqueous solution of sodium hydroxide until the liquid is a clear yellow in colour. After allowing to stand for 15-20 minutes, 2 N hydrochloric acid is added to acidify and to liberate the iodine and excess of the latter is then titrated with decinormal sodium thiosulphate in presence of starch. 

---