| 摘要 |
1,136,111. Standard gas solution. BECKMAN INSTRUMENTS Inc. 14 March, 1966 [27 April, 1965], No. 11007/66. Heading C1A. [Also in Division B1] In the preparation of an aqueous solution containing a predetermined amount of dissolved carbon dioxide, sodium bicarbonate in an amount defined by the equation (where nNaHCO 3 and nH 2 O are the number of moles of sodium bicarbonate and water, Pco 2 is the partial pressure of carbon dioxide in mm. of Hg, and K H is Henry's law constant of of equality) is reacted with an acid such as hydrochloric, sulphuric or nitric. The bicarbonate is dissolved in water in a flexible container, the atmosphere expelled by compressing the vessel and the required amount of acid added through a syringe. Alternatively, the bicarbonate may be added to an aqueous solution of the desired pH according to a further equation. A buffer, e.g. boric, phosphoric or benzoic acid, or phenol, and a thickening and a wetting agent may be added. |
