The titrimetric determination of carbon dioxide with special reference to the determination of carbon in organic compounds

✍ Scribed by R. Belcher; J.H. Thompson; T.S. West

• Publisher: Elsevier Science
• Year: 1958
• Tongue: English
• Weight: 641 KB
• Volume: 19
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/s0003-2670(00)88165-9

✦ Synopsis

INTHODUCTIoN

The method for determination of carbon dioxide by absorption in alkaline solution, followed by back-titration of the excess of alkali is well-known and widely used. The conventional absorbents are sodium hydroxide and baryta, but the latter is generally preferred because barium carbonate is sparingly soluble and does not readily redissolve at the end-point when an indicator which changes in the PH range 8 -II is used. The necessity for carrying out two titrations when sodium hydroxide is the absorbent may be avoided if the carbonate is precipitated by the addition of barium chloride. This technique was used by JOIIANSSON~, but he collected the precipitated barium carbonate which was then converted to the iodate and determined iodometrically. In most methods excess of barium chloride is present, even when baryta is used, in order to depress the solubility of the carbonate by the common ion effect. Organic solvents were used to increase the solubility of carbon dioxide by VAN NIEUWENBURG AND HEGCE~; they used a mixture of freshly distilled aniline, ethyl alcohol and baryta as absorbent. More recently R. BELCWER d d. VOL.