It's replaceable – you're not.
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.
THIAZOLES, in organic chemistry, a series of heterocyclic compounds containing the grouping shown below; the replaceable hydrogen atoms in which are designated a, (3 and µ.
For these only will the symbolic product be replaceable by a linear function of products of real coefficients.
The triazoles behave as weak bases, the imido-hydrogen being replaceable by metal.
This view, which was specially supported by Gay-Lussac and Leopold Gmelin and accepted by Berzelius, necessitated that all acids were monobasic. The untenability of this theory was proved by Thomas Graham's investigation of the phosphoric acids; for he then showed that the ortho- (ordinary), pyroand metaphosphoric acids contained respectively 3, 2 and I molecules of " basic water " (which were replaceable by metallic oxides) and one molecule of phosphoric oxide, P2 05.
A polybasic acid contains more than one atom of hydrogen which is replaceable by metals; moreover, in such an acid the replacement may be entire with the formation of normal salts, partial with the formation of acid salts, or by two or more different metals with the formation of compound salts (see Salts).
OH, termed the carboxyl group, in which the hydrogen atom is replaceable by metals with the formation of salts, and by alkyl radicals with the formation of esters.
Wislicenus found that only one hydrogen atom in the -CH 2 - group is directly replaceable by sodium, and that if the sodium be then replaced by an alkyl group, the second hydrogen atom in the group can be replaced in the same manner.
All three hydrogen atoms are replaceable by organic radicals and the resulting compounds combine with compounds of the type RC1, RBr and RI to form stibonium compounds.