Since the free acid would be dibasic, two series of salts exist, namely, the neutral and acid salts.
An acid is said to be monobasic, dibasic, tribasic, &c., according to the number of replaceable hydrogen atoms; thus HNO 3 is monobasic, sulphuric acid H 2 SO 4 dibasic, phosphoric acid H 3 PO 4 tribasic.
Kekule (Ann., 1883, 221, p. 230), however, reinvestigated this acid; he showed that it was dibasic and not tribasic; that it gave tartaric acid on reduction; and, finally, that it was dioxytartaric acid, HOOC C(OH) 2 C(OH) 2 COOH.
It is very explosive, dissolves readily in water and behaves as a dibasic acid.
When such compounds are converted into corresponding dibasic acids, CO 2 H.[CH(OH)) 3.00 2 H, the number of asymmetric carbon atoms becomes reduced from three to two, as the central carbon atom is then no longer associated with four, but with only three different radicles.
When oxidized this aldohexose is first converted into the monobasic galactonic acid, and then into dibasic mucic acid; the latter is optically inactive, so that its configuration must be one of those given in the sixth and seventh columns of the table.
Dibasic acids of the paraffin series of hydrocarbons have the general formula C n H 2 (000H) 2 "; malonic and succinic acids are important members.
It is a colourless solid and behaves as a dibasic acid.
Towards lupetidin [act' climethyl piperidine, C 5 H 9 N(CH 3) 2 1 hydrogen peroxide acts as a dibasic acid (A.
It is a dibasic acid.
With the anhydrides of dibasic acids it yields fluoresceins (q.v.).
Although nominally tribasic the commonest metallic salts are dibasic. Organic ethers, however, are known in which one, two and three of the hydrogen atoms are substituted (Michaelis and Becker, Ber., 1897, 30, p. 1003).
Sulphuric acid, being a dibasic acid, forms two series of salts with monovalent metals: an acid sulphate, Mhso 4, and a normal sulphate, M 2 50 4.
Stereo-isomerism may occur: the simplest examples are the dibasic acids, where a cis- (maleinoid) form and a trans- (fumaroid) form have been observed.
The ketones are obtained by the dry distillation of the calcium salts of dibasic saturated aliphatic acids (J.
CH 2 CH 2 ' and from the condensation of ethyl oxalate with esters of other dibasic acids in presence of sodium ethylate (W.