Solutionscirca 1830
1. Radicals
What did chemists in 1830 mean by a radical? Give an example.
A group of atoms that stays intact through a series of chemical transformations, as if it were an element. For example, the cyanide radical (CN), which Gay-Lussac observed in prussic acid and its derivatives.
2. Dumas versus Berzelius
Why did the substitution of hydrogen by chlorine without a change in properties contradict Berzelius' dualistic theory?
For Berzelius, hydrogen was electropositive and chlorine electronegative, so replacing one by the other should drastically alter the properties of the compound. In trichloroacetic acid they hardly changed: the properties also depended on the arrangement of the atoms.