| 单词 | ethereal salt |
| 释义 | > as lemmasethereal salt a. Modern Chemistry. A compound formed by the union of an acid radical with a basic radical; an acid having the whole or part of its hydrogen replaced by a metal. (In wider theoretical use the term ‘salt’ includes acids as salts of hydrogen.) Also, †ethereal salt, an ester.The first marked step towards the modern conception of a chemical salt was Rouelle's definition (a1770) of a neutral salt as a compound formed by the union of an acid with any substance serving as a base for it and giving to it a concrete or solid form. Various modifications of this or earlier views were put forward until the publication of Lavoisier's definition of a salt as the union of an acid with an oxide; this definition, however, was found to be inadequate when the composition of the halogen compounds, sulphides, etc. came to be accurately known. A further revolution in the theory of salts was made by Berzelius, who divided them into two classes; viz. haloid adj. and n. salts, formed of an electropositive element and a halogen, and amphide adj. salts, resulting from the union of an acid and a base; the latter he subdivided into oxy-salts, sulpho-salts, selenio-salts, and telluri-salts. According to more recent conceptions (Arrhenius 1888) salts, including acids, are regarded as composed of positive ions or cations (hydrogen and metals) and negative ions or anions (halogens and acid radicals). ΘΚΠ the world > matter > chemistry > chemical substances > salts > [noun] salc1386 salsature1650 salt1789 amphid1842 mercurous chloride1859 the world > matter > chemistry > organic chemistry > esters > [noun] compound ether1818 ester1852 ethereal salt1876 1789 R. Kerr tr. A. Lavoisier Elements Chem. 150–1 Acids may therefore be considered as true salifying principles... This view of the acids prevents me from considering them as salts... I shall not arrange the alkalies or earths in the class of salts, to which I allot only such as are composed of an oxygenated substance united to a base. 1807 T. Thomson Syst. Chem. (ed. 3) II. 151 [Acids] combine with all the alkalies, and most of the metallic oxides and earths, and form with them those compounds which are called salts. 1838 T. Thomson Chem. Org. Bodies 924 The tannin of areca gives a black colour to salts of iron. 1855 T. F. Hardwich Man. Photogr. Chem. 15 The principal Salts of Silver which are employed in the Photographic processes are four in number, viz. Nitrate of Silver, Chloride of Silver, Iodide of Silver, and Bromide of Silver. 1859 Todd's Cycl. Anat. & Physiol. V. 332/1 Most of the blood~salts are present in increased quantity in the gastric juice. 1876 Encycl. Brit. V. 553/2 The thio-acids also form ethereal salts. 1890 J. Walker tr. F. W. Ostwald Outl. Gen. Chem. 281 The conductivities of the neutral salts are additively composed of two values, one depending only on the metal or positive ion, the other only on the acid radical or negative ion. 1905 G. F. Goodchild & C. F. Tweney Technol. & Sci. Dict. 633/2 Salts like ethyl acetate, derived from an organic acid and an alcohol, or from an alcohol and an inorganic acid, are called ethereal salts or esters. < as lemmas |
| 随便看 |
英语词典包含1132095条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。