Formaldehyde Solution

Formaldehyde Solution Formaldehyde; CH₂O = 30.03 (50-00-0)

Analytical reagent grade of commerce containing not less than 34.0% w/v and not more than 37.0% w/v of CH₂O.

A colourless, aqueous solution with a lachrymatory vapour; weight per mL, about 1.08 g.

Assay Dilute 5 mL to 1000 mL with water. To 10 mL of the solution add 25 mL of 0.05m iodine VS and 10 mL of 1m sodium hydroxide. Allow to stand for 5 minutes, add 11 mL of 1m hydrochloric acid and titrate the excess iodine with 0.1m sodium thiosulfate VS using 1 mL of starch solution added towards the end of the titration as indicator. Each mL of 0.05m iodine VS is equivalent to 1.50 mg of CH₂O.

Store at a temperature between 15° and 25°.